Adobe Photoshop File Formats Specification November 2019 Copyright © 1991-2019 Adobe Systems Incorporated. All rights reserved. Portions Copyright © 1990-1991, Thomas Knoll. The information in this document is furnished for informational use only, is subject to change without notice, and should not be construed as a commitment by Adobe Systems Incorporated. Adobe Systems Incorporated assumes no responsibility or liability for any errors or inaccuracies that may appear in this document. The software described in this document is furnished under license and may only be used or copied in accordance with the terms of such license. Adobe, After Effects, PhotoDeluxe, Adobe Premiere, Photoshop, Adobe Illustrator, Adobe Type Manager, ATM and PostScript are either trademarks or registered trademarks of Adobe Systems Incorporated in the United States and/or other countries. Apple, Macintosh, and Mac are trademarks of Apple Computer, Inc. registered in the United States and other countries. Microsoft and Windows are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. All other products are the property of their respective owners. Preface Welcome to the Adobe Photoshop® File Format Specification! This document is the detailed specification of the Adobe Photoshop file format and other pertinent file formats that Adobe Photoshop reads and writes. Audience This document is provided for 3rd parties to read and write the Photoshop native file format. This document does not explain how to interpret the data. This document describes the format of the data only. What Is In This Document This document has three chapters: The Photoshop File Format describes the Photoshop /PSD / and /PSB / native file format in detail. Other Document File Formats discusses Photoshop's handling of the /EPS / and /TIFF / file formats, which Photoshop can also create and read. Additional File Formats describes the formats of other files used by Photoshop to store information about such items as colors, contours, curves, levels and so forth. For more information about file formats, you may wish to consult the / Encyclopedia of Graphics File Formats/ by James D. Murray & William vanRyper (1994, O'Reilly & Associates, Inc., Sebastopol, CA, ISBN 1-56592-058-9). What Is NOT In This Document This document does not have any information regarding the PSDC (Photoshop Cloud Document) that was introduced in November of 2019. That format, at this time, is private. This link will give you more information about Photoshop Cloud Documents. SDK User to User Forum The Adobe forums web page, http://www.adobe.com/support/forums , is also availble for discussion of SDK issues. From the page above follow the Photoshop link and then the Adobe Photoshop Developers link. Contents Preface Audience What Is In This Document What Is NOT In This Document SDK User to User Forum The Photoshop File Format Introduction Large Document Format Windows Mac OS Photoshop File Format File Header Section Color Mode Data Section Image Resources Section Image Resource Blocks Image Resource IDs Layer and Mask Information Section Additional Layer Information Image Data Section Other Document File Formats Photoshop EPS files TIFF files Photoshop-specific TIFF Tags TIFF Files on Mac OS Additional File Formats Actions Arbitrary Map Single active channels CMYK Setup Color Books Color Table Color Swatches Contours Curves Custom Kernel Duotone Options Halftone Screens Hue/Saturation Levels Monitor Setup Replace Color/Color Range Selective Color Separation Tables Transfer Function The Photoshop File Format Introduction This chapter discusses the Photoshop native file format /Photoshop file types / OS Filetype/extension Mac OS /8BPS/ Windows /.PSD/ Large Document Format The Large Document Format (8BPB/PSB) supports documents up to 300,000 pixels in any dimension. All Photoshop features, such as layers, effects, and filters, are supported by the PSB format. The PSB format is identical to the Photoshop native format in many ways. This document will cover the differences found in the PSB format by donating a **PSB** marker. Windows All data is stored in big endian byte order. On the Windows platform, you must byte swap short and long integers when reading or writing. Mac OS For cross-platform compatibility, all information needed by Photoshop is stored in the data fork. For interoperability with other Macintosh applications, however, some information is duplicated in resources stored in the resource fork of the file: For compatibility with image cataloging applications, the /'pnot'/ resource id 0 contains references to thumbnail, keywords, and caption information stored in other resources. The thumbnail picture is stored in a /'PICT'/ resource, the keywords are stored in /'STR#'/ resource 128 and the caption text is stored in /'TEXT'/ resource 128. For more information on the format of these resources see /Inside Macintosh: QuickTime Components/ and the /Extensis Fetch Awareness Developer's Toolkit/ . Photoshop also creates /'icl8'/ -16455 and /'ICN#'/ -16455 resources containing thumbnail images which will be shown in the Mac OS Finder. All of the data from Photoshop's File Info dialog is stored in /'ANPA'/ resource 10000. The data in this resource is stored as an IPTC-NAA record 2.For more information on the format of this resource, see the documents in the /IPTC/ folder of the /Documentation/ folder.// Photoshop File Format The Photoshop file format is divided into five major parts, as shown in the Photoshop file structure . The Photoshop file format has many length markers. Use these length markers to move from one section to the next. The length markers are usually padded with bytes to round to the nearest 2 or 4 byte interval. Photoshop file structure Photoshop File Format File header (File Header Section ). Color mode data (Color Mode Data Section ) Image resources (Image Resources Section ) Layer and mask information (Layer and Mask Information Section ) Image data (Image Data Section ). The file header has a fixed length; the other four sections are variable in length. When writing one of these sections, you should write all fields in the section, as Photoshop may try to read the entire section. Whenever writing a file and skipping bytes, you should explicitly write zeros for the skipped fields. When reading one of the length-delimited sections, use the length field to decide when you should stop reading. In most cases, the length field indicates the number of bytes, not records, following. The values in "Length" column in all tables are in bytes. All values defined as *Unicode string* consist of: A 4-byte length field, representing the number of UTF-16 code units in the string (not bytes). The string of Unicode values, two bytes per character and a two byte null for the end of the string. File Header Section The file header contains the basic properties of the image. /File header section / Length Description 4 Signature: always equal to /'8BPS'/ . Do not try to read the file if the signature does not match this value. 2 Version: always equal to 1. Do not try to read the file if the version does not match this value. (**PSB** version is 2.) 6 Reserved: must be zero. 2 The number of channels in the image, including any alpha channels. Supported range is 1 to 56. 4 The height of the image in pixels. Supported range is 1 to 30,000. (**PSB** max of 300,000.) 4 The width of the image in pixels. Supported range is 1 to 30,000. (*PSB** max of 300,000) 2 Depth: the number of bits per channel. Supported values are 1, 8, 16 and 32. 2 The color mode of the file. Supported values are: Bitmap = 0; Grayscale = 1; Indexed = 2; RGB = 3; CMYK = 4; Multichannel = 7; Duotone = 8; Lab = 9. Color Mode Data Section The color mode data section is structured as follows: /Color mode data section / Length Description 4 The length of the following color data. Variable The color data. Only indexed color and duotone (see the mode field in the File header section ) have color mode data. For all other modes, this section is just the 4-byte length field, which is set to zero. Indexed color images: length is 768; color data contains the color table for the image, in non-interleaved order. Duotone images: color data contains the duotone specification (the format of which is not documented). Other applications that read Photoshop files can treat a duotone image as a gray image, and just preserve the contents of the duotone information when reading and writing the file. Image Resources Section The third section of the file contains image resources. It starts with a length field, followed by a series of resource blocks. /Image resources section / Length Description 4 Length of image resource section. The length may be zero. Variable Image resources (Image Resource Blocks ). Image Resource Blocks Image resource blocks are the basic building unit of several file formats, including Photoshop's native file format, JPEG, and TIFF. Image resources are used to store non-pixel data associated with images, such as pen tool paths. They are referred to as resource blocks because they hold data that was stored in the Macintosh's resource fork in early versions of Photoshop. The basic structure of image resource blocks is shown in the Image resource block . The last field is the data area, which varies by resource type. The makeup of each resource type is described in the following sections. /Image resource block / Length Description 4 Signature: /'8BIM'/ 2 Unique identifier for the resource. Image resource IDs contains a list of resource IDs used by Photoshop. Variable Name: Pascal string, padded to make the size even (a null name consists of two bytes of 0) 4 Actual size of resource data that follows Variable The resource data, described in the sections on the individual resource types. It is padded to make the size even. Image Resource IDs Image resources use several standard ID numbers, as shown in the Image resource IDs . Not all file formats use all ID's. Some information may be stored in other sections of the file. For those resource IDs that have been added since Photoshop 3.0. the entry indicates the version in which they were introduced, e.g. (/ Photoshop 6.0)./ /Image resource IDs / ID Description Hex Decimal 0x03E8 1000 /(Obsolete--Photoshop 2.0 only/ ) Contains five 2-byte values: number of channels, rows, columns, depth, and mode 0x03E9 1001 Macintosh print manager print info record 0x03EA 1002 Macintosh page format information. No longer read by Photoshop. /(Obsolete)/ 0x03EB 1003 /(Obsolete--Photoshop 2.0 only/ ) Indexed color table 0x03ED 1005 /ResolutionInfo/ structure. See Appendix A in /Photoshop API Guide.pdf/. 0x03EE 1006 Names of the alpha channels as a series of Pascal strings. 0x03EF 1007 /(Obsolete) See ID 1077//DisplayInfo/ structure. See Appendix A in / Photoshop API Guide.pdf/. 0x03F0 1008 The caption as a Pascal string. 0x03F1 1009 Border information. Contains a fixed number (2 bytes real, 2 bytes fraction) for the border width, and 2 bytes for border units (1 = inches, 2 = cm, 3 = points, 4 = picas, 5 = columns). 0x03F2 1010 Background color. See See Color structure . 0x03F3 1011 Print flags. A series of one-byte boolean values (see /Page Setup/ dialog): labels, crop marks, color bars, registration marks, negative, flip, interpolate, caption, print flags. 0x03F4 1012 Grayscale and multichannel halftoning information 0x03F5 1013 Color halftoning information 0x03F6 1014 Duotone halftoning information 0x03F7 1015 Grayscale and multichannel transfer function 0x03F8 1016 Color transfer functions 0x03F9 1017 Duotone transfer functions 0x03FA 1018 Duotone image information 0x03FB 1019 Two bytes for the effective black and white values for the dot range 0x03FC 1020 /(Obsolete)/ 0x03FD 1021 EPS options 0x03FE 1022 Quick Mask information. 2 bytes containing Quick Mask channel ID; 1- byte boolean indicating whether the mask was initially empty. 0x03FF 1023 /(Obsolete)/ 0x0400 1024 Layer state information. 2 bytes containing the index of target layer (0 = bottom layer). 0x0401 1025 Working path (not saved). See See Path resource format . 0x0402 1026 Layers group information. 2 bytes per layer containing a group ID for the dragging groups. Layers in a group have the same group ID. 0x0403 1027 /(Obsolete)/ 0x0404 1028 IPTC-NAA record. Contains the /File Info.../ information. See the documentation in the /IPTC / folder of the /Documentation/ folder. 0x0405 1029 Image mode for raw format files 0x0406 1030 JPEG quality. Private. 0x0408 1032 /(Photoshop 4.0) / Grid and guides information. See See Grid and guides resource format . 0x0409 1033 /(Photoshop 4.0) / Thumbnail resource for Photoshop 4.0 only. See See Thumbnail resource format . 0x040A 1034 /(Photoshop 4.0) /Copyright flag. Boolean indicating whether image is copyrighted. Can be set via Property suite or by user in /File Info.../ 0x040B 1035 /(Photoshop 4.0) / URL. Handle of a text string with uniform resource locator. Can be set via Property suite or by user in /File Info.../ 0x040C 1036 /(Photoshop 5.0) / Thumbnail resource (supersedes resource 1033). See See Thumbnail resource format . 0x040D 1037 /(Photoshop 5.0) /Global Angle. 4 bytes that contain an integer between 0 and 359, which is the global lighting angle for effects layer. If not present, assumed to be 30. 0x040E 1038 /(Obsolete) See ID 1073 below.//(Photoshop 5.0) /Color samplers resource. See See Color samplers resource format . 0x040F 1039 /(Photoshop 5.0) /ICC Profile. The raw bytes of an ICC (International Color Consortium) format profile. See /ICC1v42_2006-05.pdf/ in the / Documentation/ folder and /icProfileHeader.h/ in /Sample Code\Common\Includes/ .// 0x0410 1040 /(Photoshop 5.0) /Watermark. One byte. 0x0411 1041 /(Photoshop 5.0) /ICC Untagged Profile. 1 byte that disables any assumed profile handling when opening the file. 1 = intentionally untagged. 0x0412 1042 /(Photoshop 5.0) /Effects visible. 1-byte global flag to show/hide all the effects layer. Only present when they are hidden. 0x0413 1043 /(Photoshop 5.0) / Spot Halftone. 4 bytes for version, 4 bytes for length, and the variable length data. 0x0414 1044 /(Photoshop 5.0) / Document-specific IDs seed number. 4 bytes: Base value, starting at which layer IDs will be generated (or a greater value if existing IDs already exceed it). Its purpose is to avoid the case where we add layers, flatten, save, open, and then add more layers that end up with the same IDs as the first set. 0x0415 1045 /(Photoshop 5.0) / Unicode Alpha Names. Unicode string 0x0416 1046 /(Photoshop 6.0)/ Indexed Color Table Count. 2 bytes for the number of colors in table that are actually defined 0x0417 1047 /(Photoshop 6.0)/ Transparency Index. 2 bytes for the index of transparent color, if any. 0x0419 1049 /(Photoshop 6.0)/ Global Altitude. 4 byte entry for altitude 0x041A 1050 /(Photoshop 6.0)/ Slices. See See Slices resource format . 0x041B 1051 /(Photoshop 6.0)/ Workflow URL. Unicode string 0x041C 1052 /(Photoshop 6.0)/ Jump To XPEP. 2 bytes major version, 2 bytes minor version, 4 bytes count. Following is repeated for count: 4 bytes block size, 4 bytes key, if key = /'jtDd'/ , then next is a Boolean for the dirty flag; otherwise it's a 4 byte entry for the mod date. 0x041D 1053 /(Photoshop 6.0)/ Alpha Identifiers. 4 bytes of length, followed by 4 bytes each for every alpha identifier. 0x041E 1054 /(Photoshop 6.0)/ URL List. 4 byte count of URLs, followed by 4 byte long, 4 byte ID, and Unicode string for each count. 0x0421 1057 /(Photoshop 6.0)/ Version Info. 4 bytes version, 1 byte / hasRealMergedData/ , Unicode string: writer name, Unicode string: reader name, 4 bytes file version. 0x0422 1058 /(Photoshop 7.0)/ EXIF data 1. See /http://www.kodak.com/global/plugins/ acrobat/en/service/digCam/exifStandard2.pdf / 0x0423 1059 /(Photoshop 7.0)/ EXIF data 3. See /http://www.kodak.com/global/plugins/ acrobat/en/service/digCam/exifStandard2.pdf / 0x0424 1060 /(Photoshop 7.0)/ XMP metadata. File info as XML description. See / http://www.adobe.com/devnet/xmp/ / 0x0425 1061 /(Photoshop 7.0)/ Caption digest. 16 bytes: RSA Data Security, MD5 message-digest algorithm 0x0426 1062 /(Photoshop 7.0)/ Print scale. 2 bytes style (0 = centered, 1 = size to fit, 2 = user defined). 4 bytes x location (floating point). 4 bytes y location (floating point). 4 bytes scale (floating point) 0x0428 1064 /(Photoshop CS)/ Pixel Aspect Ratio. 4 bytes (version = 1 or 2), 8 bytes double, x / y of a pixel. Version 2, attempting to correct values for NTSC and PAL, previously off by a factor of approx. 5%. 0x0429 1065 /(Photoshop CS)/ Layer Comps. 4 bytes (descriptor version = 16), Descriptor (see See Descriptor structure ) 0x042A 1066 /(Photoshop CS)/ Alternate Duotone Colors. 2 bytes (version = 1), 2 bytes count, following is repeated for each count: [ Color: 2 bytes for space followed by 4 * 2 byte color component ], following this is another 2 byte count, usually 256, followed by Lab colors one byte each for L, a, b. This resource is not read or used by Photoshop. 0x042B 1067 /(Photoshop CS)/Alternate Spot Colors. 2 bytes (version = 1), 2 bytes channel count, following is repeated for each count: 4 bytes channel ID, Color: 2 bytes for space followed by 4 * 2 byte color component. This resource is not read or used by Photoshop. 0x042D 1069 /(Photoshop CS2)/ Layer Selection ID(s). 2 bytes count, following is repeated for each count: 4 bytes layer ID 0x042E 1070 /(Photoshop CS2)/ HDR Toning information 0x042F 1071 /(Photoshop CS2)/ Print info 0x0430 1072 /(Photoshop CS2)/ Layer Group(s) Enabled ID. 1 byte for each layer in the document, repeated by length of the resource. NOTE: Layer groups have start and end markers 0x0431 1073 /(Photoshop CS3)/ Color samplers resource. Also see ID 1038 for old format. See See Color samplers resource format . 0x0432 1074 /(Photoshop CS3)/ Measurement Scale. 4 bytes (descriptor version = 16), Descriptor (see See Descriptor structure ) 0x0433 1075 /(Photoshop CS3)/ Timeline Information. 4 bytes (descriptor version = 16), Descriptor (see See Descriptor structure ) 0x0434 1076 /(Photoshop CS3)/ Sheet Disclosure. 4 bytes (descriptor version = 16), Descriptor (see See Descriptor structure ) 0x0435 1077 /(Photoshop CS3)//DisplayInfo/ structure to support floating point clors. Also see ID 1007. See Appendix A in /Photoshop API Guide.pdf/ . 0x0436 1078 /(Photoshop CS3)/ Onion Skins. 4 bytes (descriptor version = 16), Descriptor (see See Descriptor structure ) 0x0438 1080 /(Photoshop CS4)/ Count Information. 4 bytes (descriptor version = 16), Descriptor (see See Descriptor structure ) Information about the count in the document. See the Count Tool. 0x043A 1082 /(Photoshop CS5)/ Print Information. 4 bytes (descriptor version = 16), Descriptor (see See Descriptor structure ) Information about the current print settings in the document. The color management options. 0x043B 1083 /(Photoshop CS5)/ Print Style. 4 bytes (descriptor version = 16), Descriptor (see See Descriptor structure ) Information about the current print style in the document. The printing marks, labels, ornaments, etc. 0x043C 1084 /(Photoshop CS5)/ Macintosh NSPrintInfo. Variable OS specific info for Macintosh. NSPrintInfo. It is recommened that you do not interpret or use this data. 0x043D 1085 /(Photoshop CS5)/ Windows DEVMODE. Variable OS specific info for Windows. DEVMODE. It is recommened that you do not interpret or use this data. 0x043E 1086 /(Photoshop CS6)/ Auto Save File Path. Unicode string. It is recommened that you do not interpret or use this data. 0x043F 1087 /(Photoshop CS6)/ Auto Save Format. Unicode string. It is recommened that you do not interpret or use this data. 0x0440 1088 /(Photoshop CC)/ Path Selection State. 4 bytes (descriptor version = 16), Descriptor (see See Descriptor structure ) Information about the current path selection state. 0x07D0-0x0BB6 2000-2997 Path Information (saved paths). See See Path resource format . 0x0BB7 2999 Name of clipping path. See See Path resource format . 0x0BB8 3000 /(Photoshop CC)/ Origin Path Info. 4 bytes (descriptor version = 16), Descriptor (see See Descriptor structure ) Information about the origin path data. 0x0FA0-0x1387 4000-4999 Plug-In resource(s). Resources added by a plug-in. See the plug-in API found in the SDK documentation 0x1B58 7000 Image Ready variables. XML representation of variables definition 0x1B59 7001 Image Ready data sets 0x1B5A 7002 Image Ready default selected state 0x1B5B 7003 Image Ready 7 rollover expanded state 0x1B5C 7004 Image Ready rollover expanded state 0x1B5D 7005 Image Ready save layer settings 0x1B5E 7006 Image Ready version 0x1F40 8000 /(Photoshop CS3)/ Lightroom workflow, if present the document is in the middle of a Lightroom workflow. 0x2710 10000 Print flags information. 2 bytes version ( = 1), 1 byte center crop marks, 1 byte ( = 0), 4 bytes bleed width value, 2 bytes bleed width scale. The following sections describe some of the resource formats in more detail. Grid and guides resource format Photoshop stores grid and guides information for an image in an image resource block. Each of these resource blocks consists of an initial 16- byte grid and guide header, which is always present, followed by 5-byte blocks of specific guide information for guide direction and location, which are present if there are guides (/fGuideCount/ > 0) . /Grid and guide header / Length Description 4 Version ( = 1) 8 Future implementation of document-specific grids (4 bytes horizontal, 4 bytes vertical). Currently, sets the grid cycle to every quarter inch, i.e. 576 for both horizontal & vertical (at 72 dpi, that is 18 * 32 = 576) 4 /fGuideCount/ : Number of guide resource blocks (can be 0). /Guide resource block / Length Description 4 Location of guide in document coordinates. Since the guide is either vertical or horizontal, this only has to be one component of the coordinate. 1 Direction of guide. VHSelect is a system type of /unsigned char/ where 0 = vertical, 1 = horizontal. Grid and guide information may be modified using the Property suite. See the Callbacks chapter in /Photoshop API Guide.pdf/ for more information. Thumbnail resource format Adobe Photoshop (version 5.0 and later) stores thumbnail information for preview display in an image resource block that consists of an initial 28-byte header, followed by a JFIF thumbnail in RGB (red, green, blue) order for both Macintosh and Windows. Adobe Photoshop 4.0 stored the thumbnail information in the same format except the data section is BGR (blue, green, red). The 4.0 format is at resource ID 1033 and the 5.0 format is at resource ID 1036. /Thumbnail resource header / Length Description 4 Format. 1 = kJpegRGB . Also supports kRawRGB (0). 4 Width of thumbnail in pixels. 4 Height of thumbnail in pixels. 4 Widthbytes: Padded row bytes = (width * bits per pixel + 31) / 32 * 4. 4 Total size = widthbytes * height * planes 4 Size after compression. Used for consistency check. 2 Bits per pixel. = 24 2 Number of planes. = 1 Variable JFIF data in RGB format. For resource ID 1033 the data is in BGR format. Color samplers resource format Adobe Photoshop (version 5.0 and later) stores color samplers information for an image in an image resource block that consists of an initial 8-byte color samplers header followed by a variable length block of specific color samplers information. /Color Samplers header / Length Description 4 Version ( = 1, 2 or 3) 4 Number of color samplers to follow. See See Color Samplers resource block . /Color Samplers resource block / Length Description 4 Version of color samplers, 1 for version 3. ( Version 3 only ) . 8 The horizontal and vertical position of the point (4 bytes each). Version 1 is a fixed value. Version 2 is a float value. 2 Color Space: enum { colorCodeDummy = -1, RGB, HSB, CMYK, Pantone, Focoltone, Trumatch, Toyo, Lab, Gray, WideCMYK, HKS, DIC, TotalInk, MonitorRGB, Duotone, Opacity, Web, GrayFloat, RGBFloat, OpacityFloat}; 2 Depth ( Version 2 only ) Path resource format Photoshop stores the paths saved with an image in an image resource block. These resource blocks consist of a series of 26-byte path point records, so the resource length should always be a multiple of 26. Photoshop stores its paths as resources of type /8BIM/ , with IDs in the range 2000 through 2997. These numbers should be reserved for Photoshop. The name of the resource is the name given to the path when it was saved. If the file contains a resource of type /8BIM/ with an ID of 2999, then this resource contains a Pascal-style string containing the name of the clipping path to use with this image when saving it as an EPS file. 4 byte fixed value for flatness and 2 byte fill rule. 0 = same fill rule, 1 = even odd fill rule, 2 = non zero winding fill rule. The fill rule is ignored by Photoshop. The path format returned by /GetProperty()/ call is identical to what is described below. Refer to the /IllustratorExport/ sample plug-in code to see how this resource data is constructed. Path points All points used in defining a path are stored in eight bytes as a pair of 32-bit components, vertical component first. The two components are signed, fixed point numbers with 8 bits before the binary point and 24 bits after the binary point. Three guard bits are reserved in the points to eliminate most concerns over arithmetic overflow. Hence, the range for each component is /0xF0000000/ to /0x0FFFFFFF/ representing a range of -16 to 16. The lower bound is included, but not the upper bound. This limited range is used because the points are expressed relative to the image size. The vertical component is given with respect to the image height, and the horizontal component is given with respect to the image width. [/0,0/ ] represents the top-left corner of the image; [/1,1/ ] ([/0x01000000,0x01000000/ ]) represents the bottom-right. In Windows, the byte order of the path point components are reversed; you should swap the bytes when accessing each 32-bit value. Path records The data in a path resource consists of one or more 26-byte records. The first two bytes of each record is a selector to indicate what kind of path it is. For Windows, you should swap the bytes before accessing it as a short. /Path data record types / Selector Description 0 Closed subpath length record 1 Closed subpath Bezier knot, linked 2 Closed subpath Bezier knot, unlinked 3 Open subpath length record 4 Open subpath Bezier knot, linked 5 Open subpath Bezier knot, unlinked 6 Path fill rule record 7 Clipboard record 8 Initial fill rule record The first 26-byte path record contains a selector value of 6, path fill rule record. The remaining 24 bytes of the first record are zeroes. Paths use even/odd ruling. Subpath length records, selector value 0 or 3, contain the number of Bezier knot records in bytes 2 and 3. The remaining 22 bytes are unused, and should be zeroes. Each length record is then immediately followed by the Bezier knot records describing the knots of the subpath. In Bezier knot records, the 24 bytes following the selector field contain three path points (described above) for: the control point for the Bezier segment preceding the knot, the anchor point for the knot, and the control point for the Bezier segment leaving the knot. Linked knots have their control points linked. Editing one point modifies the other to preserve collinearity. Knots should only be marked as having linked controls if their control points are collinear with their anchor. The control points on unlinked knots are independent of each other. Refer to the /Adobe Photoshop User Guide/ for more information. Clipboard records, /selector=7/ , contain four fixed-point numbers for the bounding rectangle (top, left, bottom, right), and a single fixed- point number indicating the resolution. Initial fill records, /selector=8/ , contain one two byte record. A value of 1 means that the fill starts with all pixels. The value will be either 0 or 1. Slices resource format Adobe Photoshop 6.0 stores slices information for an image in an image resource block. Adobe Photoshop 7.0 added a descriptor at the end of the block for the individual slice info. Adobe Photoshop CS and later changed to version 7 or 8 and uses a Descriptor to defined the Slices data. /Slices header for version 7 or 8 / Length Description 4 Version ( = 7 and 8) 4 Descriptor version ( = 16 for Photoshop 6.0). Variable Descriptor (see See Descriptor structure ) /Slices header for version 6 / Length Description 4 Version ( = 6) 4 * 4 Bounding rectangle for all of the slices: top, left, bottom, right of all the slices Variable Name of group of slices: Unicode string 4 Number of slices to follow. See Slices resource block in the next table. /Slices resource block / Length Description 4 ID 4 Group ID 4 Origin 4 Associated Layer ID Only present if Origin = 1 Variable Name: Unicode string // 4 Type 4 * 4 Left, top, right, bottom positions Variable URL: Unicode string Variable Target: Unicode string Variable Message: Unicode string Variable Alt Tag: Unicode string 1 Cell text is HTML: Boolean Variable Cell text: Unicode string 4 Horizontal alignment 4 Vertical alignment 1 Alpha color 1 Red 1 Green 1 Blue Additional data as length allows. See comment above. 4 Descriptor version ( = 16 for Photoshop 6.0). Variable Descriptor (see See Descriptor structure ) Vanishing point resource format Adobe Photoshop CS2 (9.0) and later stores vanishing point information for an image in an image resource block. The entire resource is a string with an id of 'tnaF' on Windows and 'FaNt' on the Macintosh. The structure of the resource is as follows: Vocabulary: Relation - a set of related planes. Root Plane - the first plane in a relation. Calibration Order - an ordering of the planes in a relation starting with the root plane, depth first, recursive traversal of the planes that are attached to the given plane. Basics: A planes area is represented as a clipped area of vanish rays. A Ray defines one of the virtual sides of the plane's area. A Ray's structure keeps track of information needed for tearing off and orientation issues. Parallel rays must point at the same VPID. A Primary ray's origin represents the point on the plane that is farthest from both VPs. The two primary rays share an origin. version = 101 number of relations to follow. -- for each relation-- grid resolution for the root plane number of planes to follow -- for each plane in calibration order-- ID of the plane ID of the plane that calibrates this plane 0 if none -- for 4 rays -- origin position of the ray. Point VP location - must be consistent across all planes in the relation unless it is an endpoint. Point true if the VP location is an endpoint ID that this ray points at. Ray DI (see below) ++++++++++++++++++++ I/O appendix Point - two doubles; h endl, v endl VPID - int (enum value) 0,1,2 identifing 1 of 3 possible VPs RayID - 1, One of the primary rays directly connected to the shared origin 3, a non-primary ray parallel to 7 5, a non-primary ray parallel to 1 7, One of the primary rays directly connected to the shared origin . Layer and Mask Information Section The fourth section of a Photoshop file contains information about layers and masks. This section of the document describes the formats of layer and mask records. The complete merged image data is not stored here. The complete merged/ composite image resides in the last section of the file. See See Image Data Section . If maximize compatibility is unchecked then the merged/composite is not created and the layer data must be read to reproduce the final image. See Layer and mask information section shows the overall structure of this section. If there are no layers or masks, this section is just 4 bytes: the length field, which is set to zero. (**PSB** length is 8 bytes 'Layr', 'Lr16' and 'Lr32' start at See Layer info . NOTE: The length of the section may already be known.) When parsing this section pay close attention to the length of sections. /Layer and mask information section / Length Description 4 Length of the layer and mask information section. (**PSB** length is 8 bytes.) Variable Layer info (see See Layer info for details). Variable Global layer mask info (see See Global layer mask info for details). Variable /(Photoshop 4.0 and later)/ Series of tagged blocks containing various types of data. See /See Additional Layer Information / // for the list of the types of data that can be included here. See Layer info shows the high-level organization of the layer information. /Layer info / Length Description 4 Length of the layers info section, rounded up to a multiple of 2. (**PSB** length is 8 bytes.) 2 Layer count. If it is a negative number, its absolute value is the number of layers and the first alpha channel contains the transparency data for the merged result. Variable Information about each layer. See Layer records describes the structure of this information for each layer. Variable Channel image data. Contains one or more image data records (see See Channel image data for structure) for each layer. The layers are in the same order as in the layer information (previous row of this table). /Layer records / Length Description 4 * 4 Rectangle containing the contents of the layer. Specified as top, left, bottom, right coordinates 2 Number of channels in the layer 6 * number of channels Channel information. Six bytes per channel, consisting of: 2 bytes for Channel ID: 0 = red, 1 = green, etc.; -1 = transparency mask; -2 = user supplied layer mask, -3 real user supplied layer mask (when both a user mask and a vector mask are present) 4 bytes for length of corresponding channel data. (**PSB** 8 bytes for length of corresponding channel data.) See /See Channel image data / for structure of channel data.// 4 Blend mode signature: /'8BIM'/ 4 Blend mode key: 'pass' = pass through, 'norm' = normal, 'diss' = dissolve, 'dark' = darken, 'mul ' = multiply, 'idiv' = color burn, 'lbrn' = linear burn, 'dkCl' = darker color, 'lite' = lighten, 'scrn' = screen, 'div ' = color dodge, 'lddg' = linear dodge, 'lgCl' = lighter color, 'over' = overlay, 'sLit' = soft light, 'hLit' = hard light, 'vLit' = vivid light, 'lLit' = linear light, 'pLit' = pin light, 'hMix' = hard mix, 'diff' = difference, 'smud' = exclusion, 'fsub' = subtract, 'fdiv' = divide 'hue ' = hue, 'sat ' = saturation, 'colr' = color, 'lum ' = luminosity, 1 Opacity. 0 = transparent ... 255 = opaque 1 Clipping: 0 = base, 1 = non-base 1 Flags: bit 0 = transparency protected; bit 1 = visible; bit 2 = obsolete; bit 3 = 1 for Photoshop 5.0 and later, tells if bit 4 has useful information; bit 4 = pixel data irrelevant to appearance of document 1 Filler (zero) 4 Length of the extra data field ( = the total length of the next five fields). Variable Layer mask data: See See Layer mask / adjustment layer data for structure. Can be 40 bytes, 24 bytes, or 4 bytes if no layer mask. Variable Layer blending ranges: See See Layer blending ranges data . Variable Layer name: Pascal string, padded to a multiple of 4 bytes. /Layer mask / adjustment layer data / Length Name 4 Size of the data: Check the size and flags to determine what is or is not present. If zero, the following fields are not present 4 * 4 Rectangle enclosing layer mask: Top, left, bottom, right 1 Default color. 0 or 255 1 Flags. bit 0 = position relative to layer bit 1 = layer mask disabled bit 2 = invert layer mask when blending (Obsolete) bit 3 = indicates that the user mask actually came from rendering other data bit 4 = indicates that the user and/or vector masks have parameters applied to them 1 Mask Parameters. Only present if bit 4 of Flags set above. Variable Mask Parameters bit flags present as follows: bit 0 = user mask density, 1 byte bit 1 = user mask feather, 8 byte, double bit 2 = vector mask density, 1 byte bit 3 = vector mask feather, 8 bytes, double 2 Padding. Only present if size = 20. Otherwise the following is present 1 Real Flags. Same as Flags information above. 1 Real user mask background. 0 or 255. 4 * 4 Rectangle enclosing layer mask: Top, left, bottom, right. /Layer blending ranges data / Length Name 4 Length of layer blending ranges data 4 Composite gray blend source. Contains 2 black values followed by 2 white values. Present but irrelevant for Lab & Grayscale. 4 Composite gray blend destination range 4 First channel source range 4 First channel destination range 4 Second channel source range 4 Second channel destination range ... ... 4 Nth channel source range 4 Nth channel destination range /Channel image data / Length Description 2 Compression. 0 = Raw Data, 1 = RLE compressed, 2 = ZIP without prediction, 3 = ZIP with prediction. Variable Image data. If the compression code is 0, the image data is just the raw image data, whose size is calculated as /(LayerBottom-LayerTop)* (LayerRight- LayerLeft)/ (from the first field in See Layer records ). If the compression code is 1, the image data starts with the byte counts for all the scan lines in the channel /(LayerBottom-LayerTop)/ , with each count stored as a two-byte value.(**PSB** each count stored as a four-byte value.) The RLE compressed data follows, with each scan line compressed separately. The RLE compression is the same compression algorithm used by the Macintosh ROM routine PackBits, and the TIFF standard. If the layer's size, and therefore the data, is odd, a pad byte will be inserted at the end of the row. If the layer is an adjustment layer, the channel data is undefined (probably all white.) /Global layer mask info / Length Description 4 Length of global layer mask info section. 2 Overlay color space (undocumented). 8 4 * 2 byte color components 2 Opacity. 0 = transparent, 100 = opaque. 1 Kind. 0 = Color selected--i.e. inverted; 1 = Color protected;128 = use value stored per layer. This value is preferred. The others are for backward compatibility with beta versions. Variable Filler: zeros Additional Layer Information There are several types of layer information that have been added in Photoshop 4.0 and later. These exist at the end of the layer records structure (see the last row of See Layer records ). They have the following structure: /Additional layer information / Length Description 4 Signature: /'8BIM'/ or /'8B64'/ 4 Key: a 4-character code (See individual sections) 4 Length data below, rounded up to an even byte count. (**PSB**, the following keys have a length count of 8 bytes: LMsk, Lr16, Lr32, Layr, Mt16, Mt32, Mtrn, Alph, FMsk, lnk2, FEid, FXid, PxSD. Variable Data (See individual sections) The following sections describe the different types of data available, their keys and their format. Adjustment layer /(Photoshop 4.0)/ Adjustment layers can have one of the following keys: '/SoCo/' = Solid Color '/GdFl/' = Gradient '/PtFl/' = Pattern '/brit/' = Brightness/Contrast '/levl/' = Levels '/curv/' = Curves '/expA/' = Exposure '/vibA/' = Vibrance '/hue /' = Old Hue/saturation, Photoshop 4.0 '/hue2/' = New Hue/saturation, Photoshop 5.0 '/blnc/' = Color Balance '/blwh/' = Black and White '/phfl/' = Photo Filter '/mixr/' = Channel Mixer '/clrL/' = Color Lookup '/nvrt/' = Invert '/post/' = Posterize '/thrs/' = Threshold '/grdm/' = Gradient Map '/selc/' = Selective color The data for the adjustment layer is the same as the load file formats for each format. See See Additional File Formats for information. Effects Layer /(Photoshop 5.0)/ The key for the effects layer is /'lrFX'/ . The data has the following format: /Effects Layer info / Length Description 2 Version: 0 2 Effects count: may be 6 (for the 6 effects in Photoshop 5 and 6) or 7 (for Photoshop 7.0) The next three items are repeated for each of the effects. 4 Signature: /'8BIM'/ 4 Effects signatures: OSType key for which effects type to use: 'cmnS' = common state (see See Effects layer, common state info ) 'dsdw' = drop shadow (see See Effects layer, drop shadow and inner shadow info ) 'isdw' = inner shadow (see See Effects layer, drop shadow and inner shadow info ) 'oglw' = outer glow (see See Effects layer, outer glow info ) 'iglw' = inner glow (see See Effects layer, inner glow info ) 'bevl' = bevel (see See Effects layer, bevel info ) 'sofi' = solid fill (/Photoshop 7.0) / (see See Effects layer, solid fill (added in Photoshop 7.0) ) Variable See appropriate tables. /Effects layer, common state info / Length Description 4 Size of next three items: 7 4 Version: 0 1 Visible: always true 2 Unused: always 0 /Effects layer, drop shadow and inner shadow info / Length Description 4 Size of the remaining items: 41 or 51 (depending on version) 4 Version: 0 (/Photoshop 5.0) / or 2 (/Photoshop 5.5)/ 4 Blur value in pixels 4 Intensity as a percent 4 Angle in degrees 4 Distance in pixels 10 Color: 2 bytes for space followed by 4 * 2 byte color component 8 Blend mode: 4 bytes for signature and 4 bytes for key 1 Effect enabled 1 Use this angle in all of the layer effects 1 Opacity as a percent 10 Native color: 2 bytes for space followed by 4 * 2 byte color component /Effects layer, outer glow info / Length Description 4 Size of the remaining items: 32 for Photoshop 5.0; 42 for 5.5 4 Version: 0 for Photoshop 5.0; 2 for 5.5 4 Blur value in pixels. 4 Intensity as a percent 10 Color: 2 bytes for space followed by 4 * 2 byte color component 8 Blend mode: 4 bytes for signature and 4 bytes for the key 1 Effect enabled 1 Opacity as a percent 10 /(Version 2 only) / Native color space. 2 bytes for space followed by 4 * 2 byte color component /Effects layer, inner glow info / Length Description 4 Size of the remaining items: 33 for Photoshop 5.0; 43 for 5.5 4 Version: 0 for Photoshop 5.0; 2 for 5.5. 4 Blur value in pixels. 4 Intensity as a percent 10 Color: 2 bytes for space followed by 4 * 2 byte color component 8 Blend mode: 4 bytes for signature and 4 bytes for the key 1 Effect enabled 1 Opacity as a percent Remaining fields present only in version 2 1 Invert 10 /(Version 2 only) / Native color space. 2 bytes for space followed by 4 * 2 byte color component /Effects layer, bevel info // / Length Description 4 Size of the remaining items (58 for version 0, 78 for version 20 4 Version: 0 for Photoshop 5.0; 2 for 5.5 4 Angle in degrees 4 Strength. Depth in pixels 4 Blur value in pixels. 8 Highlight blend mode: 4 bytes for signature and 4 bytes for the key 8 Shadow blend mode: 4 bytes for signature and 4 bytes for the key 10 Highlight color: 2 bytes for space followed by 4 * 2 byte color component 10 Shadow color: 2 bytes for space followed by 4 * 2 byte color component 1 Bevel style 1 Hightlight opacity as a percent 1 Shadow opacity as a percent 1 Effect enabled 1 Use this angle in all of the layer effects 1 Up or down The following are present in version 2 only 10 Real highlight color: 2 bytes for space; 4 * 2 byte color component 10 Real shadow color: 2 bytes for space; 4 * 2 byte color component /Effects layer, solid fill (added in Photoshop 7.0) / Length Description 4 Size: 34 4 Version: 2 4 Key for blend mode 10 Color space 1 Opacity 1 Enabled 10 Native color space Type Tool Info /(Photoshop 5.0 and 5.5 only)/ Has been superseded in Photoshop 6.0 and beyond by a different structure with the key /'TySh'/ (see /See Type tool object setting (Photoshop 6.0) / /See Type tool object setting / ). Key is /'tySh'/ . Data is as follows: /Type tool Info / Length Description 2 Version ( = 1) 48 6 * 8 double precision numbers for the transform information /Font information/ 2 Version ( = 6) 2 Count of faces The next 8 fields are repeated for each count specified above 2 Mark value 4 Font type data Variable Pascal string of font name Variable Pascal string of font family name Variable Pascal string of font style name 2 Script value 4 Number of design axes vector to follow 4 Design vector value /Style information/ 2 Count of styles The next 10 fields are repeated for each count specified above 2 Mark value 2 Face mark value 4 Size value 4 Tracking value 4 Kerning value 4 Leading value 4 Base shift value 1 Auto kern on/off 1 Only present in version <= 5 1 Rotate up/down /Text information/ 2 Type value 4 Scaling factor value 4 Sharacter count value 4 Horizontal placement 4 Vertical placement 4 Select start value 4 Select end value 2 Line count, i.e. the number of items to follow. The next 5 fields are repeated for each item in line count. 4 Character count value 2 Orientation value 2 Alignment value 2 Actual character as a double byte character 2 Style value /Color information/ 2 Color space value 8 4 * 2 byte color component 1 Anti alias on/off// Unicode layer name/(Photoshop 5.0)/ Key is /'luni'/ . Data is as follows: /Unicode Layer name / Length Description Variable Unicode string Layer ID /(Photoshop 5.0)/ Key is /'lyid'/ . /Layer ID // / Length Description 4 Signature: /'8BIM'/ 4 Key: /'lyid'/ 4 Length: 4 4 ID. Object-based effects layer info/(Photoshop 6.0)/ Key is /'lfx2'/ . Data is as follows: /Object Based Effects Layer info / Length Description 4 Object effects version: 0 4 Descriptor version ( = 16 for Photoshop 6.0). Variable Descriptor (see See Descriptor structure ) Patterns/(Photoshop 6.0 and CS (8.0))/ This is a list of patterns. Key is/'Patt', 'Pat2' or 'Pat3'/ . Data is as follows: /Patterns / Length Description The following is repeated for each pattern. 4 Length of this pattern 4 Version ( =1) 4 The image mode of the file. Supported values are: Bitmap = 0; Grayscale = 1; Indexed = 2; RGB = 3; CMYK = 4; Multichannel = 7; Duotone = 8; Lab = 9. 4 Point: vertical, 2 bytes and horizontal, 2 bytes Variable Name: Unicode string Variable Unique ID for this pattern: Pascal string Variable Index color table (256 * 3 RGB values): only present when image mode is indexed color Variable Pattern data as Virtual Memory Array List /Virtual Memory Array List / Length Description 4 Version ( =3) 4 Length 16 Rectangle: top, left, bottom, right 4 Number of channels The following is a /virtual memory array/, repeated for the number of channels + one for a user mask + one for a sheet mask.// 4 Boolean indicating whether array is written, skip following data if 0. 4 Length, skip following data if 0. 4 Pixel depth: 1, 8, 16 or 32 16 Rectangle: top, left, bottom, right 2 Pixel depth: 1, 8, 16 or 32 1 Compression mode of data to follow. 1 is zip. Variable Actual data based on parameters and compression Annotations/(Photoshop 6.0)/ Key is /'Anno'/ . Data is as follows: /Annotations / Length Description 2 Major version ( = 2) 2 Minor version. ( = 1) 4 Count of annotations to follow Following is repeated for each annotation 4 Length of this annotation 4 Annotation type: either text(/'txtA'/ ) or sound (/'sndA'/ ). 1 Is the annotation open 1 Flags. // 2 Optional blocks. ( =1 for Photoshop 6.0) 16 Rectangle of icon location: top, left, bottom and right. 16 Rectangle of popup locations: top, left, bottom and right 10 2 bytes for space followed by 4 * 2 byte color component Variable Pascal string of author's name aligned to 2 bytes Variable Pascal string of name aligned to 2 bytes Variable Pascal string of the mod Date aligned to 2 bytes 4 Length of the following 3 fields including this field 4 '/txtC/ ' or '/sndM/ '. Either text or sound 4 Length of the next field Variable Actual data for this annotation. The text is an ASCII or Unicode string; the sound annotation is documented in the /PDF Reference/ , available at /http:// Partners.adobe.com/asn/developer/acrosdk/docs.html#filefmtspecs / Variable Padding to align to multiple of 4 bytes Blend clipping elements /(Photoshop 6.0)/ Key is /'clbl'/ . Data is as follows: /Blend clipping elements / Length Description 1 Blend clipped elements: boolean 3 Padding Blend interior elements /(Photoshop 6.0)/ Key is/'infx'/ . Data is as follows: /Blend interior elements / Length Description 1 Blend interior elements: boolean 3 Padding Knockout setting/(Photoshop 6.0)/ Key is /'knko'/ . Data is as follows: /Knockout setting / Length Description 1 Knockout: boolean 3 Padding Protected setting /(Photoshop 6.0)/ Key is /'lspf'/ . Data is as follows: /Protected setting / Length Description 4 Protection flags: bits 0 - 2 are used for Photoshop 6.0. Transparency, composite and position respectively. Sheet color setting /(Photoshop 6.0)/ Key is /'lclr'/ . Data is as follows: /Sheet Color setting / Length Description 4 * 2 Color. Only the first color setting is used for Photoshop 6.0; the rest are zeros Reference point /(Photoshop 6.0)/ Key is /'fxrp'/ . Data is as follows: /Reference point / Length Description 2 * 8 2 double values for the reference point Gradient settings /(Photoshop 6.0)/ Key is /'grdm'/ . Data is as follows: /Gradient settings / Length Description 2 Version ( =1 for Photoshop 6.0) 1 Is gradient reversed 1 Is gradient dithered Variable Name of the gradient: Unicode string, padded 2 Number of color stops to follow Following is repeated for each color stop 4 Location of color stop 4 Midpoint of color stop 2 Mode for the color to follow 4 * 2 Actual color for the stop 2 Number of transparency stops to follow Following is repeated for each transparency stop 4 Location of transparency stop 4 Midpoint of transparency stop 2 Opacity of transparency stop 2 Expansion count ( = 2 for Photoshop 6.0) 2 Interpolation if length above is non-zero 2 Length (= 32 for Photoshop 6.0) 2 Mode for this gradient 4 Random number seed 2 Flag for showing transparency 2 Flag for using vector color 4 Roughness factor 2 Color model 4 * 2 Minimum color values 4 * 2 Maximum color values 2 Dummy: not used in Photoshop 6.0 Section divider setting /(Photoshop 6.0)/ Key is /'lsct'/ . Data is as follows: /Section Divider setting / Length Description 4 Type. 4 possible values, 0 = any other type of layer, 1 = open "folder", 2 = closed "folder", 3 = bounding section divider, hidden in the UI Following is only present if length >= 12 4 Signature: /'8BIM'/ 4 Key. See blend mode keys in See Layer records . Following is only present if length >= 16 4 Sub type. 0 = normal, 1 = scene group, affects the animation timeline. Channel blending restrictions setting /(Photoshop 6.0)/ Key is /'brst'/ . Data is as follows: /Channel blending restrictions setting / Length Description Following is repeated length / 4 times. 4 Channel number that is restricted Solid color sheet setting /(Photoshop 6.0)/ Key is /'SoCo'/ . Data is as follows: /Solid color sheet setting / Length Description 4 Version ( = 16 for Photoshop 6.0) Variable Descriptor. Based on the Action file format structure (see See Descriptor structure ) Pattern fill setting /(Photoshop 6.0)/ Key is /'PtFl'/ . Data is as follows: /Pattern fill setting / Length Description 4 Version ( =16 for Photoshop 6.0) Variable Descriptor. Based on the Action file format structure (see See Descriptor structure )// Gradient fill setting/(Photoshop 6.0)/ Key is /'GdFl'/ . Data is as follows: /Gradient Fill Setting / Length Description 4 bytes Version ( = 16 for Photoshop 6.0) Variable Descriptor. Based on the Action file format structure (see See Descriptor structure )// Vector mask setting /(Photoshop 6.0)/ Key is /'vmsk'/ or /'vsms'/. If key is /'vsms'/ then we are writing for /(Photoshop CS6)/ and the document will have a /'vscg' / key. Data is as follows: /Vector mask setting / Length Description 4 Version ( = 3 for Photoshop 6.0) 4 Flags. bit 1 = invert, bit 2 = not link, bit 3 = disable The rest of the data is path components, loop until end of the length. Variable Paths. See See Path resource format Type tool object setting/(Photoshop 6.0)/ This supersedes the type tool info in Photoshop 5.0 (see See Type tool Info ). Key is /'TySh'/ . Data is as follows: /Type tool object setting / Length Description 2 Version ( =1 for Photoshop 6.0) 6 * 8 Transform: xx, xy, yx, yy, tx, and ty respectively. 2 Text version ( = 50 for Photoshop 6.0) 4 Descriptor version ( = 16 for Photoshop 6.0) Variable Text data (see See Descriptor structure ) 2 Warp version ( = 1 for Photoshop 6.0) 4 Descriptor version ( = 16 for Photoshop 6.0) Variable Warp data (see See Descriptor structure ) 4 * 8 left, top, right, bottom respectively. Foreign effect ID/(Photoshop 6.0)/ Key is /'ffxi'/ . Data is as follows: /Foreign effect ID / Length Description 4 ID of the Foreign effect. Layer name source setting/(Photoshop 6.0)/ Key is /'lnsr'/ . Data is as follows: /Layer name source setting / Length Description 4 ID for the layer name Pattern data/(Photoshop 6.0)/ Key is /'shpa'/ . Data is as follows: /Pattern data / Length Description 4 Version ( = 0 for Photoshop 6.0) 4 Count of sets to follow The following is repeated for the count above. 4 Pattern signature 4 Pattern key 4 Count of patterns in this set 1 Copy on sheet duplication 3 Padding The following is repeated for the count of patterns above. 4 Color handling. Prefer convert = /'conv'/ , avoid conversion = /'avod'/ , luminance only = /'lumi'/ Variable Pascal string name of the pattern Variable Unicode string name of the pattern Variable Pascal string of the unique identifier for the pattern Metadata setting/(Photoshop 6.0)/ Key is /'shmd'/ . Data is as follows: /Metadata setting / Length Description 4 Count of metadata items to follow The following is repeated the number of times specified by the count above: 4 Signature of the data 4 Key of the data 1 Copy on sheet duplication 3 Padding 4 Length of data to follow Variable Undocumented data Layer version /(Photoshop 7.0)/ Key is /'lyvr'/ . Data is as follows: /Layer version / Length Description 4 A 32-bit number representing the version of Photoshop needed to read and interpret the layer without data loss. 70 = 7.0, 80 = 8.0, etc. The minimum value is 70, because just having the field present in 6.0 triggers a warning. For the future, Photoshop 7 checks to see whether this number is larger than the current version -- i.e., 70 -- and if so, warns that it is ignoring some data. Transparency shapes layer /(Photoshop 7.0)/ Key is /'tsly'/ . Data is as follows: /Transparency shapes layer / Length Description 1 1: the transparency of the layer is used in determining the shape of the effects. This is the default for behavior like previous versions. 0: treated in the same way as fill opacity including modulating blend modes, rather than acting as strict transparency. Using this feature is useful for achieving effects that otherwise would require complex use of clipping groups. 3 Padding Layer mask as global mask /(Photoshop 7.0)/ Key is /'lmgm'/ . Data is as follows: /Layer mask as global mask / Length Description 1 1: the layer mask is used in a final crossfade masking the layer and effects rather than being used to shape the layer and its effects. This behavior was previously tied to the link status flag for the layer mask. (An unlinked mask acted like a flag value of 1, a linked mask like 0). For old files that lack this key, the link status is used in order to preserve compositing results. 3 Padding Vector mask as global mask /(Photoshop 7.0)/ Key is /'vmgm'/ . Data is as follows: /Vector mask as global mask / Length Description 1 Same as in See Layer mask as global mask , but applying the vector mask. 3 Padding Brightness and Contrast// Key is /'brit'/ . Data is as follows: /Brightness and Contrast / Length Description 2 Brightness 2 Contrast 2 Mean value for brightness and contrast 1 Lab color only Channel Mixer// Key is /'mixr'/ . Data is as follows: /Channel Mixer / Length Description 2 Version ( = 1) 2 Monochrome 20 RGB or CMYK color plus constant for the mixer settings. 4 * 2 bytes of color with 2 bytes of constant. Color Lookup /(Photoshop CS6)/ Key is /'clrL'/ . Data is as follows: /Color Lookup / Length Description 2 Version ( = 1) 4 Descriptor Version ( = 16) Variable Descriptor of black and white information Placed Layer (replaced by SoLd in Photoshop CS3) Key is /'plLd'/ . Data is as follows: /Placed Layer / Length Description 4 Type ( = 'plcL' ) 4 Version ( = 3 ) Variable Unique ID as a pascal string 4 Page number 4 Total pages 4 Anit alias policy 4 Placed layer type: 0 = unknown, 1 = vector, 2 = raster, 3 = image stack 4 * 8 Transformation: 8 doubles for x,y location of transform points 4 Warp version ( = 0 ) 4 Warp descriptor version ( = 16 ) Variable Descriptor for warping information Linked Layer Key is /'lnkD'/ . Also keys /'lnk2'/ and /'lnk3'/ . Data is as follows: /Linked Layer / Length Description The following is repeated for each linked file. 8 Length of the data to follow 4 Type ( = 'liFD' linked file data, 'liFE' linked file external or 'liFA' linked file alias ) 4 Version ( = 1 to 7 ) Variable Pascal string. Unique ID. Variable Unicode string of the original file name 4 File Type 4 File Creator 8 Length of the data to follow 1 File open descriptor Variable Descriptor of open parameters. Only present when above is true. If the type is 'liFE' then a linked file Descriptor is next. Variable Descriptor of linked file parameters. See comment above. If the type is 'liFE' and the version is greater than 3 then the following is present. Year, Month, Day, Hour, Minute, Second is next. 4 Year 1 Month 1 Day 1 Hour 1 Minute 8 Double for the seconds If the type is 'liFE' then a file size is next. 8 File size If the type is 'liFA' then 4 zeros are next. 8 All zeros If the type is 'liFE' then they bytes of the file are next. Variable Raw bytes of the file. If the version is greater than or equal to 5 then the following is next. UnicodeString Child Document ID. If the version is greater than or equal to 6 then the following is next. Double Asset mod time. If the version is greater than or equal to 7 then the following is next. 1 Asset locked state, for Libraries assets. If the type is 'liFE' and the version is 2 then the following is next. Variable Raw bytes of the file. Photo Filter Key is /'phfl'/ . Data is as follows: /Photo Filter / Length Description 2 Version ( = 3) or ( = 2 ) 12 4 bytes each for XYZ color (Only in Version 3) 10 2 bytes color space followed by 4 * 2 bytes color component (Only in Version 2) 4 Density 1 Preserve Luminosity Black White /(Photoshop CS3)/ Key is /'blwh'/ . Data is as follows: /Black White / Length Description 4 Descriptor Version ( = 16) Variable Descriptor of black and white information Content Generator Extra Data /(Photoshop CS5)/ Key is /'CgEd'/ . Data is as follows: /Content Generator Extra Data / Length Description 4 Descriptor Version ( = 16) Variable Descriptor of extra data Text Engine Data /(Photoshop CS3)/ Key is /'Txt2'/ . Data is as follows: /Text Engine Data / Length Description 4 Length of data to follow Variable Raw bytes for text engine Vibrance /(Photoshop CS3)/ Key is /'vibA'/ . Data is as follows: /Vibrance / Length Description 4 Descriptor Version ( = 16) Variable Descriptor of vibrance information Unicode Path Name /(Photoshop CS6)/ Key is /'pths'/ . Data is as follows: /Unicode Path Name / Length Description 4 Descriptor Version ( = 16) Variable Descriptor containing a list of unicode path names Animation Effects /(Photoshop CS6)/ Key is /'anFX'/ . Data is as follows: /Animation Effects / Length Description 4 Descriptor Version ( = 16) Variable Descriptor containing animation effects Filter Mask /(Photoshop CS3)/ Key is /'FMsk'/ . Data is as follows: /Filter Mask / Length Description 10 Color space 2 Opacity Placed Layer Data /(Photoshop CS3)/ Key is /'SoLd'/ . See also /*'PlLd'*/ key. Data is as follows: /Filter Mask / Length Description 4 Identifier ( = 'soLD' ) 4 Version ( = 4 ) 4 Descriptor Version ( = 16) Variable Descriptor of placed layer information Vector Stroke Data /(Photoshop CS6)/ Key is /'vstk'/ . Data is as follows: /Vector stroke setting / Length Description 4 Version ( = 16 ) Variable Descriptor. Based on the Action file format structure (see See Descriptor structure )// Vector Stroke Content Data /(Photoshop CS6)/ Key is /'vscg'/ . Data is as follows: /Vector stroke content setting / Length Description 4 Key for data 4 Version ( = 16 ) Variable Descriptor. Based on the Action file format structure (see See Descriptor structure )// Using Aligned Rendering /(Photoshop CS6)/ Key is /'sn2P'/ . Data is as follows: /Using Aligned Rendering / Length Description 4 Non zero is true for using aligned rendering Vector Origination Data /(Photoshop CC)/ Key is /'vogk'/ . Data is as follows: /Vector origination setting / Length Description 4 Version ( = 1 for Photoshop CC) 4 Version ( = 16 ) Variable Descriptor. Based on the Action file format structure (see See Descriptor structure )// Pixel Source Data /(Photoshop CC)/ Key is /'PxSc'/. Data is as follows: /Pixel Source info / Length Description 4 Version ( = 16 ) Variable Descriptor. Based on the Action file format structure (see See Descriptor structure )// Compositor Used /(Photoshop 2020)/ Key is /'cinf'/. Data is as follows: /Compositor Used / Length Description 4 Version ( = 16 ) Variable Descriptor. Based on the Action file format structure (see See Descriptor structure )// Pixel Source Data /(Photoshop CC 2015)/ Key is /'PxSD'/. Data is as follows: /Pixel Source info / Length Description 8 Length of data to follow Variable Raw data for 3D or video layers. Artboard Data /(Photoshop CC 2015)/ Key is /'artb'/ or /'artd'/ or /'abdd'/. Data is as follows: /Artboard info / Length Description 4 Version ( = 16 ) Variable Descriptor. Based on the Action file format structure (see See Descriptor structure )// Smart Object Layer Data /(Photoshop CC 2015)/ Key is /'SoLE'/ . Data is as follows: /Smart Object info / Length Description 4 Type ( = 'soLD' ) 4 Version ( = 4 or 5 ) Variable Descriptor. Based on the Action file format structure (see See Descriptor structure )// Saving Merged Transparency Key is /'Mtrn', 'Mt16' or 'Mt32'/ . There is no data associated with these keys. User Mask Key is /'LMsk'/ . /User Mask / Length Description 10 Color space 2 Opacity 1 Flag ( = 128 ) Exposure Key is /'expA'/ . /Exposure / Length Description 2 Version (= 1) 4 Exposure 4 Offset 4 Gamma Filter Effects Key is /'FXid' or 'FEid'/ . /Filter Effects / Length Description 4 Version ( =1, 2 or 3) 8 Length of data to follow The following is repeated for the given length. Variable Pascal string as identifier 4 Version ( = 1 ) 8 Length 16 Rectangle: top, left, bottom, right 4 Depth 4 Max channels The following is repeated for number of channels + a user mask + a sheet mask.// 4 Boolean indicating whether array is written 8 Length 2 Compression mode of data to follow. Variable Actual data based on compression End of repeating for channels 1 Next two items present or not 2 Compression mode of data to follow Variable Actual data based on compression Image Data Section The last section of a Photoshop file contains the image pixel data. Image data is stored in planar order: first all the red data, then all the green data, etc. Each plane is stored in scan-line order, with no pad bytes, /Image data section / Length Description 2 Compression method: 0 = Raw image data 1 = RLE compressed the image data starts with the byte counts for all the scan lines (rows * channels), with each count stored as a two-byte value. The RLE compressed data follows, with each scan line compressed separately. The RLE compression is the same compression algorithm used by the Macintosh ROM routine /PackBits/ , and the TIFF standard. 2 = ZIP without prediction 3 = ZIP with prediction. Variable The image data. Planar order = RRR GGG BBB, etc. Other Document File Formats Photoshop EPS files The following summarizes the additional information Photoshop writes when creating EPS files: Photoshop writes a high-resolution bounding box comment to the EPS file immediately following the traditional EPS bounding box comment. The comment begins with "/%%HiResBoundingBox/ " and is followed by four numbers identical to those given for the bounding box except that they can have fractional components (i.e., a decimal point and digits after it). The traditional bounding box is written as the rounded version of the high resolution bounding box for compatibility. Photoshop writes its image resources out to a block of data stored as follows: %BeginPhotoshop: // /EPS parameters for BeginPhotoshop / Field Definition length Length of the image resource data. hex data Image resource data in hexadecimal. Photoshop includes a comment in the EPS files it writes so that it is able to read them back in again. Third party programs that write pixel- based EPS files may want to include this comment in their EPS files, so Photoshop can read their files. The comment must follow immediately after the /%%/ comment block at the start of the file. The comment is: %ImageData: "" // /EPS parameters for ImageData / Field Definition columns Width of the image in pixels. rows Height of the image in pixels. depth Number of bits per channel. Must be 1 or 8. mode Image mode. Bitmap/grayscale = 1; Lab = 2; RGB = 3; CMYK = 4. pad channels Number of other channels store in the file. Ignored when reading. Photoshop uses this to include a grayscale image that is printed on non- color PostScript printers. block size Number of bytes per row per channel. Will be either 1 or formula (below): 1 = Data is interleaved. /(columns*depth+7)/8/ =Data is stored in line-interleaved format, or there is only one channel. binary/ascii 1 = Data is in binary format. 2 = Data is in hex ascii format. data start Entire PostScript line immediately preceding the image data. This entire line should not occur elsewhere in the PostScript header code, butit may occur at part of a line. TIFF files See TIFF Tags describes the standard TIFF (version 6) tags and tag values that Photoshop is able to read and write. Photoshop reads the first Image File Directory (IFD) and writes one IFD per file. In addition, Photoshop uses a set of tags that are not defined in the TIFF v6 specification to store specific information. See See Photoshop- specific TIFF Tags . See See TIFF Files on Mac OS for information about how TIFF files are stored on Macintosh. /TIFF Tags / Tag Name Photoshop reads Photoshop writes 254 NewSubFileType Ignored 0 256 ImageWidth 1 to 30000 1 to 30000 257 ImageLength 1 to 30000 1 to 30000 258 BitsPerSample 1, 2, 4, 8, 16 (all same) 1, 8, 16 259 Compression 1 (uncompressed), 2 (CCITT), 5 (LZW), 7 (JPEG), 8 (ZIP), 32773 (PackBits) 1, 5, 7, 8 262 PhotometricInterpretation 0, 1, 2, 3, 5, 8, 9 0 (1-bit), 1 (8-bit), 2, 3,5,8 266 FillOrder 1 No 270 ImageDescription Printing Caption Printing Caption 271 EXIF: Make 272 EXIF: Model 273 StripOffsets Yes Yes 277 SamplesPerPixel 1 to 24 1 to 24 278 RowsPerStrip Any Single strip if not compressed, multiple strips if compressed. 279 StripByteCounts Required if compressed Yes 282 XResolution Yes Yes 283 YResolution Ignored (square pixels assumed) Yes 284 PlanarConfiguration 1 or 2 1 296 ResolutionUnit 2 or 3 2 305 EXIF: Software 306 EXIF: Date/time 315 EXIF: Artist 317 Predictor 1 or 2 1 or 2 320 ColorMap Yes Yes 322 TileWidth Yes No 323 TileLength Yes No 324 TileOffsets Yes No 325 TileByteCounts Required if compressed No 332 InkSet 1 No 336 DotRange Yes, if CMYK Yes 338 ExtraSamples Ignored (except for count) Photoshop 5.5 and earlier writes 0. Photoshop 6.0 and later writes 0 or 1 based on the spec. See /Photoshop TIFF.pdf/ for additional information about tags 259 and 262.// Photoshop-specific TIFF Tags /Photoshop-specific TIFF tags / Tag Description 330 /tSubIFD/ . Documented in the /TIFF-PM6.pdf / file as a PageMaker extension 437 JPEG tables. See /Photoshop TIFF.pdf/ for more information.// 700 XMP metadata. See /http://www.adobe.com/devnet/xmp/ / 33723 File information (IPTC-NAA record 2: see the documents in the /IPTC/ folder of the /Documentation/ folder). 34377 Photoshop image resources (see See Image Resources Section ) 34665 EXIF IFD pointer. See /http://www.kodak.com/global/plugins/acrobat/en/ service/digCam/exifStandard2.pdf / 34675 ICC Profiles (see the /ICC1v42_2006-05.pdf/ file from the International Color Consortium in the /Documentation/ folder of the Photoshop SDK) 34853 EXIF GPS info. See /http://www.kodak.com/global/plugins/acrobat/en/ service/digCam/exifStandard2.pdf / 37724 /tImageSourceData/ . Begins with the null-terminated string "/Adobe Photoshop Document Data Block/ ", (**PSB** "/Adobe Photoshop Document Data V0002/ "), followed by data of various types. See /Photoshop TIFF.pdf/ for a list . 50255 /tAnnotations/ . See See Annotations for details. TIFF Files on Mac OS For cross-platform compatibility, all information in a Macintosh TIFF file is stored in the data fork. For interoperability with other Mac OS applications, however, some information is duplicated in resources stored in the resource fork of the file. For compatibility with image cataloging applications, the /'pnot'/ resource id 0 contains references to thumbnail, keywords, and caption information stored in other resources. The thumbnail picture is stored in a /'PICT'/ resource, the keywords are stored in /'STR#'/ resource 128 and the caption text is stored in /'TEXT'/ resource 128. For more information on the format of these resources see /Inside Macintosh: QuickTime Components/ and the /Extensis Fetch Awareness Developer's Toolkit/ . All of the data from Photoshop's /File Info/ dialog is stored in /'ANPA'/ resource 10000. /'STR '/ resource -16396 contains a string indicating the application that created the TIFF file. Photoshop also creates /'icl8'/ -16455 and /'ICN#'/ -16455 resources containing thumbnail images which are shown in the Mac OS Finder. Additional File Formats In addition to documents that the user creates in Adobe Photoshop (discussed in See The Photoshop File Format ), there are a number of additional files used by Photoshop to store information about such items as colors, contours, curves, levels and so forth. These are known as / load files./ This chapter describes the format of each load file. Some of the files can saved by the user; others are load only, as indicated in the sections. Each file has a unique file type and file extension associated with it. Photoshop for Macintosh recognizes either, but does not require the use of the extension. In the file dialogs, Photoshop for Windows looks for files with the given file extension automatically; this can be overridden. Under Mac OS, all information is stored in the data forks of Photoshop's load files. The files are completely interchangable with Windows or any other platform. Consistent byte ordering is required across platforms when reading and writing load files. Photoshop stores multi-byte values with the high- order bytes first, (big-endian), as on Mac OS., which is the opposite of Windows' standard byte order.. For more information, see "Macintosh and Windows development" in chapter 2 of /Photoshop API Guide.pdf/ . Actions Actions are accessed by means of the Actions palette. The object effects use the actions mechanism to output information to the PSD file format.// /Action file types / OS Filetype/extension Mac OS /8BAC/ Windows /.ATN/ Each action file comprises an /action set/ . The format of the action file is described in the table below: /Action file format / Length Description 4 Version ( = 16) Variable Unicode string: action set name 1 Boolean: true if set is expanded for the Actions palette 4 Number of actions in action set The following is repeated for each action in the set 2 Index of action// 1 Boolean: true if Shift key needed for keyboard shortcut 1 Boolean: true if Command key needed for keyboard shortcut 2 Color index information Variable Unicode string: action name 1 Boolean: true if action is expanded in the Actions palette 4 Number of items in action The following is repeated for each item 1 Boolean: true if action is expanded in the Actions palette 1 Boolean: true if action is enabled 1 Boolean: true if dialogs should be displayed 1 Options for displaying dialogs 4 Identifier: /'TEXT'/ or /'long'/ Variable Event: if identifier is /'TEXT'/ ,4 bytes of length followed by the string; if identifier is /'long'/ , 4 bytes of itemID// Variable Dictionary name: 4 bytes of length followed by the string// 4 -1 if a descriptor follows or 0 for none. Variable Descriptor: see Descriptor structure (See Descriptor structure ) for details /Descriptor structure / Length Description Variable Unicode string: name from classID Variable classID: 4 bytes (length), followed either by string or (if length is zero) 4-byte classID 4 Number of items in descriptor The following is repeated for each item in descriptor Variable Key: 4 bytes ( length) followed either by string or (if length is zero) 4-byte key 4 Type: OSType key 'obj ' = Reference 'Objc' = Descriptor 'VlLs' = List 'doub' = Double 'UntF' = Unit float 'TEXT' = String 'enum' = Enumerated 'long' = Integer 'comp' = Large Integer 'bool' = Boolean 'GlbO' = GlobalObject same as Descriptor 'type' = Class 'GlbC' = Class 'alis' = Alias 'tdta' = Raw Data Variable Item type: see the tables below for each possible type /Reference Structure / Length Description 4 Number of items The following is repeated for each item in reference 4 OSType key for type to use: 'prop' = Property 'Clss' = Class 'Enmr' = Enumerated Reference 'rele' = Offset 'Idnt' = Identifier 'indx' = Index 'name' =Name Variable Item type: see the tables below for each possible Reference type /Property Structure / Length Description Variable Unicode string: name from classID Variable classID: 4 bytes (length), followed either by string or (if length is zero) 4-byte classID Variable KeyID: 4 bytes (length), followed either by string or (if length is zero) 4-byte keyID '#Pnt' = points: tagged unit value '#Mlm' = millimeters: tagged unit value /Unit float structure / Length Description 4 Units the following value is in. One of the following: '#Ang' = angle: base degrees '#Rsl' = density: base per inch '#Rlt' = distance: base 72ppi '#Nne' = none: coerced. '#Prc'= percent: unit value '#Pxl' = pixels: tagged unit value 8 Actual value (double) /Double structure / Length Description 8 Actual value (double) /Class structure / Length Description Variable Unicode string: name from classID Variable ClassID: 4 bytes (length), followed either by string or (if length is zero) 4-byte classID /String structure / Length Description Variable String value as Unicode string /Enumerated reference / Length Description Variable Unicode string: name from ClassID. Variable ClassID: 4 bytes (length), followed either by string or (if length is zero) 4-byte classID Variable TypeID: 4 bytes (length), followed either by string or (if length is zero) 4-byte typeID Variable enum: 4 bytes (length), followed either by string or (if length is zero) 4-byte enum /Offset structure / Length Description Variable Unicode string: name from ClassID Variable ClassID: 4 bytes (length), followed either by string or (if length is zero) 4-byte classID 4 Value of the offset /Boolean structure / Length Description 1 Boolean value /Alias structure / Length Description 4 Length of data to follow Variable /FSSpec/ for Macintosh or a handle to a string to the full path on Windows /List structure / Length Description 4 Number of items in the list The following is repeated for each item in list 4 OSType key for type to use. See See Descriptor structure for types. Variable See the tables above for each possible type /Large Integer / Length Description 8 Value /Integer / Length Description 4 Value /Enumerated descriptor / Length Description Variable Type: 4 bytes (length), followed either by string or (if length is zero) 4-byte typeID// Variable Enum: 4 bytes (length), followed either by string or (if length is zero) 4-byte enum /Raw Data / Length Description Variable Value Arbitrary Map Arbitrary Map files are accessed by means of the Curves dialog (/load only/ ).// /Arbitrary map file types / OS Filetype/extension Mac OS /8BLT/ Windows /.AMP/ There is no version number written in the file. The files are an even multiple of 256 bytes long. Each 256 bytes is a lookup table, where: The first byte of the table corresponds to byte zero of the image. The last byte of the table corresponds to byte 255 of the image. A /NULL/ table that has no effect on an image is a linear table of bytes from 0 to 255. If the file has one table, it is applied to the image's channels according to these priorities: If the image has a master composite channel, the table is applied to it. If not, then: If the image has a single active channel, the table is applied to it. If not, then: If the image has no composite channel and more than one active channel, the table is not applied. If the file has exactly three tables, it is applied to the image's channels according to these priorities: The tables are assumed to represent RGB lookups. They are applied to the first three channels in the image, leaving the master composite untouched. Or: If the image has a single active channel, the tables are converted to grayscale and the result is applied to the active channel. Or: The first table is treated as a master. The remaining tables are applied to the image channels in turn (second table is applied to first channel, third table is applied to second channel, etc.). Single active channels Photoshop handles single active channels in a special fashion. When saving a map applied to a single channel, only one table is written to the file. Similarly, when reading a file for application to a single active channel, the master table is the one that will be used on that channel. This allows easy application of a single file to both composite and grayscale images. CMYK Setup CMYK settings files are accessed in Photoshop's Color Settings dialog / (load only)/ . // /CMYK file types / OS Filetype/extension Mac OS /8BIC/ Windows /.API/ /CMYK setup file format / Length Description 2 Version ( = 7) 27*2 Nine sets of three short integers specifying th\e /xyY/ (CIE) values for the inks and their combinations. The inks are specified in the order cyan, magenta, yellow, magenta-yellow (red), cyan-yellow (green), cyan- magenta (blue), cyan-magenta-yellow, followed by the white and black points. Each set is written in the order /xyY/ where: /x/ = 0...10000, representing 0.0...1.0000. /y/ = 1...10000, representing 0.0001...1.0000. /Y/ = 0...20000, representing 0.00...200.00. 2 Dot gain. Short integer from -10...40, representing -10%...40%. 1 Use curves. = 1 if curves table present. 1 Filler: zero 13*4*2 Only present if "use curves" = 1. 4 sets of 13 short integers specifyting the cyan, magenta, yellow, and black curve percentages from the Dot Gain Curves dialog. 0...1000, representing 0.0...100.0 % Variable Separation setup: see See Separation file format /Separation file format / Length Description 2 Version ( = 300) 2 Separation type. 0 = UCR separations; 1 = GCR separations 2 Blank ink limit (0...100) 2 Total ink limit (200...400) 2 Undercolor addition for GCR separations (0...100) Variable Black generation (spline) curve detailed in See Black generation curve data structure . See also the Curves data format in See Curves file format . /Black generation curve data structure / Length Description 2 Number of points in curve ( 2...19) 2* number of points Each curve point is a pair of short integers where the first number is the output value (vertical coordinate on the Black Generation dialog graph) and the second is the input value. All coordinates have range 0 to 255. A /NULL/ curve (no change to image data) is represented by the following five-number, ten-byte sequence in a file: 2 0 0 255 255. The black generation curve and the UCA limit must both be present even if the separation type is set to UCR ( = 0). Color Books Color book files /(Photoshop 7.0) / are automatically loaded by Photoshop; they cannot be saved or loaded via a menu item. You can place custom color books into the /Presets\Color Books/ folder. Use the / Custom/ button on the Adobe color picker to access them.// /Color book file types / OS Filetype/extension Mac OS /8BCB/ Windows /.ACB/ /Color book file format / Length Description 4 Signature: /8BCB/ 2 Version ( =1 ) 2 Book ID. Existing IDs: 3000 (ANPA), 3001 (Focoltone), 3002 (PantoneCoated), 3003 (PantoneProcess), 3004 (PantoneProSlim), 3005 (PantoneUncoated), 3006 (Toyo), 3007 (Trumatch), 3008 (HKSE), 3009 (HKSK), 3010 (HKSN), 3011 (HKSZ), 3012 (DIC), 3020 (PantonePastelCoated), 3021 (PantonePastelUncoated), 3022 (PantoneMetallic) Variable Unicode string: title Variable Unicode string: prefix Variable Unicode string: postfix Variable Unicode string: description 2 Number of colors (<= 8000) 2 Colors per page (<= 9) 2 Key color page; must be less than or equal to colers per page 2 Color type. 0 = RGB; 2 = CMYK; 7 = Lab The following are repeated for the number of colors Variable Unicode string: name 6 Unique key for the color 4 Color values: 4 bytes for CMYK; 3 bytes for RGB and Lab Color Table Color Table files are accessed using the Colors palette /(load only)/ .// /Color table file types / OS Filetype/extension Mac OS /8BCT/ Windows /.ACT/ There is no version number written in the file. The file is 768 or 772 bytes long and contains 256 RGB colors. The first color in the table is index zero. There are three bytes per color in the order red, green, blue. If the file is 772 bytes long there are 4 additional bytes remaining. Two bytes for the number of colors to use. Two bytes for the color index with the transparency color to use. If loaded into the Colors palette, the colors will be installed in the color swatch list as RGB colors. Color Swatches Color swatch files are loaded and saved in Photoshop's Color Swatches palette. These are typically stored in the /Color Swatches / sub- directory in the /Presets/ directory.// /Color swatches file types / OS Filetype/extension Mac OS /8BCO/ Windows /.ACO/ /Color swatches file format / Length Description 2 Version ( =1 ) 2 Count of colors in the file. count *10 Colors. Each color is 10 bytes, as described in See Color structure . At the end of a version 1 file is the version 2 information. 2 Version ( = 2 ) 2 Count of colors in the file. The next two fields are repeated for each count. count *10 Colors. Each color is 10 bytes, as described in See Color structure . Variable Unicode string: color name. /Color structure / Length Description 2 The color space the color belongs to (see See Color space IDs ). 8 Four short unsigned integers with the actual color data. If the color does not require four values, the extra values are undefined and should be written as zeros. See See Color space IDs . /Color space IDs / Color ID Description 0 RGB. The first three values in the color data are /red/ , /green/ , and / blue/ . They are full unsigned 16-bit values as in Apple's /RGBColor/ data structure. Pure red = 65535, 0, 0. 1 HSB. The first three values in the color data are /hue/ , /saturation/ , and /brightness/ . They are full unsigned 16-bit values as in Apple's / HSVColor/ data structure. Pure red = 0,65535, 65535. 2 CMYK. The four values in the color data are /cyan/ , /magenta/ , /yellow/ , and /black/ . They are full unsigned 16-bit values. 0 = 100% ink. For example, pure cyan = 0,65535,65535,65535. 7 Lab. The first three values in the color data are /lightness/ , /a chrominance/ , and /b chrominance/ . Lightness is a 16-bit value from 0...10000. Chrominance components are each 16-bit values from -12800...12700. Gray values are represented by chrominance components of 0. Pure white = 10000,0,0. 8 Grayscale. The first value in the color data is the gray value, from 0...10000. Photoshop allows the specification of custom colors, such as those colors that are defined in a set of custom inks provided by a printing ink manufacturer. These colors can be stored in the Colors palette and streamed to and from load files. The details of a custom color's color data fields are not public and should be treated as a black box. See Custom color spaces gives the color space IDs currently defined by Photoshop for some custom color spaces. /Custom color spaces / Color ID Name 3 Pantone matching system 4 Focoltone colour system 5 Trumatch color 6 Toyo 88 colorfinder 1050 10 HKS colors Contours Contour settings files /(Photoshop 6.0) / are loaded and saved in Photoshop's Layer Effects dialog. /Contour file types / OS Filetype/extension Mac OS /8BFS/ Windows /.SHC/ /Contour file format / Length Description 4 Type ( = /'8BFS'/ ) 2 Version ( = 1 ) 4 Count of contours The following is repeated for each contour 4 Version ( = 1 or 2) Variable Unicode string: contour name Variable version 1 or 2 data follows. See See Contours Version 1 for version 1 and See Contours Version 2 for version 2. /Contours Version 1 / Length Description 2 Count of points 4* count For each point: 4 bytes of point data (2 bytes vertical, 2 bytes horizontal_ 4 Minimum input range 4 Maximum input range /Contours Version 2 / Length Description 2 Count of points 4 * count For each point: Point data (2 bytes vertical, 2 bytes horizontal) 1 * count For each point: boolean indicating whether the point is continuous 4 Min input range 4 Max input range Curves Curves settings files are loaded in Photoshop's Curves dialog and Black Generation curve dialog (from within Separation Setup Preferences). Curves files can also be loaded into any of Photoshop's transfer function dialogs, such as the Duotone Curve dialog from within Duotone Options, and Print transfer dialog. Curves are saved as /.ATF/ and /.ACV/ files. When loaded into a transfer function dialog, only the first curve in a Curves file is used. /Curves file types / OS Filetype/extension Mac OS /8BSC/ Windows /.CRV/ /Curves file format / Length Description 2 Version ( = 1 or = 4) 2 Version 1 = bit map of curves in file Version 4 = count of curves in the file The following is the data for each curve specified by count above 2 Count of points in the curve (short integer from 2...19) point count * 4 Curve points. Each curve point is a pair of short integers where the first number is the output value (vertical coordinate on the Curves dialog graph) and the second is the input value. All coordinates have range 0 to 255. See also See Null curves below. Null curves A /NULL/ curve (no change to image data) is represented by the following five-number, ten-byte sequence in a file: 2 0 0 255 255 Displaying ink percentages Photoshop allows the option of displaying ink percentages instead of pixel values; this is a display option only and the internal data is unchanged, with 100% ink equal to image data of 0 and 0% ink equal to image data of 255. Curves data order The first curve is a master curve that applies to all the composite channels (RGB) when in composite image mode. The remaining curves apply to the active channels in order: curve two applies to channel one, curve three applies to channel two, etc., up until curve 17, which applies to channel 16. Indexed color The exception to the normal order, and the reason there are up to 19 curves, is when the mode is Indexed color. In this case: The first curve is a master curve. The next three curves are created for the Red, Green, and Blue portions of the image's color table, and they are applied to the first channel. The remaining curves apply to any remaining alpha channel that is active: for instance, if channel two is active, curve five applies to it; if channel three is active, curve six applies to it, etc., up until curve 19, which applies to channel 16. Single active channels Photoshop handles single active channels in a special fashion. When saving the curves applied to a single channel, the settings are stored into the master curve, at the beginning of the file. Similarly, when reading a curves file for application to a single active channel, the master curve is the one that will be used on that channel. This allows easy application of a single file to both RGB and grayscale images. Additional information At the end of the Version 1 file is the following information: Extra level record info marker 'Crv ' /Extra curves marker / Length Description 4 = 'Crv ' for extra curve information 2 Version ( = 4) 4 Count of items to follow. The following is the data for each curve specified by count above 2 Before each curve is a channel index. 2 Count of points in the curve (short integer from 2...19) point count * 4 Curve points. Each curve point is a pair of short integers where the first number is the output value (vertical coordinate on the Curves dialog graph) and the second is the input value. All coordinates have range 0 to 255. See also See Null curves below. Custom Kernel Kernel settings files are loaded and saved in Photoshop's Custom Filter dialog.// . /Custom kernel file types / OS Filetype/extension Mac OS /8BCK/ Windows /.ACF/ /Custom filter structure / Length Description 50 Weights. The first 25 values are the custom weights from -999...999, applied to pixels offset from each pixel by [-2,-2] to [2,2]. The values progress through horizontal offsets first, as follows: {[-2,-2],[-1,-2],[ 0,-2],[ 1,-2],[ 2,-2], [-2,-1],[-1,-1],[ 0,-1],[ 1,-1],[ 2,-1], [-2, 0],[-1, 0],[ 0, 0],[ 1, 0],[ 2, 0], [-2, 1],[-1, 1],[ 0, 1],[ 1, 1],[ 2, 1], [-2, 2],[-1, 2],[ 0, 2],[ 1, 2],[ 2, 2]} 27*2 Ink colors. Nine sets of three short integers specifying the /xyY/ (CIE) values for the inks and their combinations. The inks are specified in the order cyan, magenta, yellow, magenta-yellow (red), cyan-yellow (green), cyan- magenta (blue), cyan-magenta-yellow, followed by the white and black points. Each set is written in the order /xyY/ where: /x/ = 0...10000, representing 0.0...1.0000. /y/ = 1...10000, representing 0.0001...1.0000. /Y/ = 0...20000, representing 0.00...200.00. 2 Scale. Short integer from 1...9999. 2 Offset. Short integer from -9999...9999. Duotone Options Duotone settings files are loaded and saved in the Duotone Options dialog..// /Duotone file types / OS Filetype/extension Mac OS /8BDT/ Windows /.ADO/ /Duotone file format / Length Description 2 Version ( = 1) 2 /Count/ . Number of plates in duotone spec (short integer). 1 = Monotone; 2 = Duotone; 3 = Tritone; 4 = Quadtone. 4*10 Four ink colors, regardless of the number of plates. The contents of the colors beyond the last plate specified by Count are undefined. Each color is 10 bytes and described in See Duotone color structure . It is identical to the format in a Colors load file. 4*64 Four ink names, regardless of the number of plates. Each name is streamed as a Pascal-style string with a length byte followed by the string name. Names may not be more than 63 characters. Each name is padded to occupy 64 bytes, including the length byte. Any names beyond the last plate specified by /Count/ should be empty, size = 0. 4*28 Four ink curves, regardless of the number of plates. Described in See Ink curves structure . 2 Dot gain ( = 20). Kept for compatability with Photoshop 2.0. Ignored. 11*10 Eleven overprint colorscolors, regardless of the number of plates. The number of defined overprints depends on /Count/ . Monotones = no overprint colors. Duotones = one overprint color. Tritones = four overprint colors. Quadtones = 11 overprint colors. The contents of the colors beyond the last defined overprint are undefined. Each color is 10 bytes and described in See Duotone color structure . It is identical to the format in a Colors load file. /Duotone color structure / Length Description 2 The color space the color belongs to (see See Color space IDs ). 8 Four short unsigned integers with the actual color data. If the color does not require four values to specify, the extra values are undefined and should be written as zeros. /Ink curves structure / Length Description 26 Transfer curve: Array of 13 short integers from 0...1000 representing 0.0...100.0. All but the first and last value may be -1, representing no point on the curve. Any curves beyond the last plate should be equal to the /NULL/ curve. A /NULL/ transfer curve looks like this: 0, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1000. 2 Override ( = 0). Short integer for compatibility. Ignored by Photoshop 3.0 and higher. // Halftone Screens Halftone Screens settings files are loaded and saved in Photoshop's Halftone Screens dialog (available from /Edit > Print with Preview/ in Photoshop 7, or /Page Setup/ or /Print Options/ in previous versions).// /Halftone screen file types / OS Filetype/extension Mac OS /8BHS/ Windows /.AHS/ /Halftone screens file format / Length Description 2 Version ( = 5) 4*18 Four screen descriptions. See See Halftone screen parameter structure . Variable For every screen that has a custom spot function, the PostScript function text is written here, one after the other, with no header information, in the same order as the screen settings. The size of each custom spot is the absolute value of its negative shape code. /Halftone screen parameter structure / Length Description 4 Ink's screen frequency, in lines per inch. Binary fixed point value ;16 bits representing the integer and fractional parts from 1.0...999.999. 2 Units for the screen frequency. Lines per inch = 1; lines per centimeter = 2. Only affects display, not screen frequency. 4 Angle for screen. Binary fixed point value with 16 bits representing the integer and fractional parts from -180.0000 ... 180.0000, measured in degrees. 2 Code representing the shape of the halftone dots. 0 = Round; 1 = Ellipse; 2 = Line; 3 = Square; 4 = Cross; 6 = Diamond. Negative numbers represent custom shapes; the absolute value is the size in bytes of the custom spot function described in See Halftone screens file format . 4 = 0. Not currently used by Photoshop. 1 Boolean. 1 = Use accurate screens; 0 = Use other. 1 Boolean. 1 = Use printer's default screens; 0 = Use other. Hue/Saturation Hue/Saturation settings files are loaded and saved in Photoshop's Hue/ Saturation dialog.// /Hue/saturation file types / OS Filetype/extension Mac OS /8BHA/ Windows /.AHU/ /Hue/saturation file format / Length Description 2 Version ( = 2) 1 0 = Use settings for hue-adjustment; 1 = Use settings for colorization. 1 Padding byte; must be present but is ignored by Photoshop. 6 Colorization. Photoshop 5.0: The actual values are stored for the new version. Hue is -180...180, Saturation is 0...100, and Lightness is -100...100. Photoshop 4.0: Three short integers Hue, Saturation, and Lightness from -100...100. The user interface represents hue as -180...180, saturation as 0...100, and Lightness as -100...100, as the traditional HSB color wheel, with red = 0. 6 Master hue, saturation and lightness values. 6 sets of the following 14 bytes (4 range values followed by 3 settings values) 8: range values For RGB and CMYK, those values apply to each of the six hextants in the HSB color wheel: those image pixels nearest to red, yellow, green, cyan, blue, or magenta. These numbers appear in the user interface from -60...60, however the slider will reflect each of the possible 201 values from -100...100. For Lab, the first four of the six values are applied to image pixels in the four Lab color quadrants, yellow, green, blue, and magenta. The other two values are ignored ( = 0). The values appear in the user interface from -100 to 100. 6:settings values Levels Levels settings files are loaded and saved in the Levels dialog.// /Levels file types / OS Filetype/extension Mac OS /8BLS/ Windows /.ALV/ /Levels file format / Length Description 2 Version ( = 2) 29 * 10 29 sets of level records, each level containing 5 short integers (see See Level record structure ). /Level record structure / Length Description 2 Input floor (0...253) 2 Input ceiling (2...255) 2 Output floor (0...255). Matched to input floor. 2 Output ceiling (0...255) 2 Gamma. Short integer from 10...999 representing 0.1...9.99. Applied to all image data. Level record sets order The first set of levels is the master set that applies to all of the composite channels (RGB) when in composite image mode. The remaining sets apply to the active channels individually; set two applies to channel one, the set three to channel two, etc., up until set 25, which applies to channel 24. Sets 28 and 29 are reserved and should be set to zeros. Indexed color The exception to the normal order is when the mode is Indexed: The first set is a master set. The next three sets are created for the Red, Green, and Blue portions of the image's color table, and they are applied to the first channel. The remaining sets apply to any remaining alpha channels that are active: for instance, if channel two is active, set five applies to it; if channel three is active, set six applies to it, etc., up until channel 27, which applies to channel 24. Sets 28 and 29 are reserved and should be set to zeros. Single active channels Photoshop handles single active channels in a special fashion. When saving the levels applied to a single channel, the settings are stored into the master set, at the beginning of the file. Similarly, when reading a levels file for application to a single active channel, the master levels are the ones that will be used on that channel. This allows easy application of a single file to both RGB and grayscale images. Photoshop CS (8.0) Additional information At the end of the Version 2 file is the following information: Extra level record info marker 'Lvls' /Extra levels marker / Length Description 4 = 'Lvls' for extra level information 2 Version ( = 3) 2 Count of total level record structures. Subtract the legacy number of level record structures, 29, to determine how many are remaining in the file for reading. Variable Additianol level records according to count. See Level record structure Monitor Setup This format has been superseded by ICC profiles. See / ICC1v42_2006-05.pdf/ for details.// Monitor settings files are accessed in Photoshop's Color Settings dialog, via the /Edit/ menu /(load only)/ .// // /Monitor setup file types / OS Filetype/extension Mac OS /8BMS/ Windows /.AMS/ /Monitor setup file format / Length Description 2 Version ( = 2.) 2 Gamma. Short integer from 75...300 representing 0.75...3.00. 2*2 White point. Two short integers as CIE chromaticity coordinates: / x,y/ . /x/ = 0...10000 representing 0.0...1.0000. /y/ = 1...10000 representing 0.0001...1.0000. 6*2 Phosphors. Three sets of two integers giving /x,y/ coordinates of the red, green, and blue phosphors. /x/ = 0...10000 representing 0.0...1.0000. /y/ = 1...10000 representing 0.0001...1.0000. In the order /red/ /x/ , /red/ /y/ ; /green/ /x/ , /green / /y/ ; /blue / / x/ , /blue/ /y/ . Replace Color/Color Range Replace Color settings files are loaded and saved in the Color Range dialog (available via the /Select/ menu).// /Replace color/Color range file types / OS Filetype/extension Mac OS /8BXT/ Windows /.AXT/ /Replace color/Color range file format / Length Description 2 Version ( = 1) 2 Short integer indicating what space the color components are in. 7 = Lab color, 8 = grayscale. No other values are supported. 6 Component ranges. Six unsigned byte values representing the range of colors within which a pixel's color must fall to be considered selected for color replacement, or color range selecting. Described in See Component range structure . 2 Fuzziness. Short integer from 0...200 controlling how colors close to selected colors are affected. 6 Transform settings. When used with Replace Color: Three short integers from -100...100. Described in See Replace color transform settings . When used with Color Range: Writes zeros into the three short integers and ignores. /Component range structure / Length Description 1 if Lab (color space = 7): low endpoint of /L/ value if grayscale (color space = 8): low endpoint of gray range 1 if Lab: high endpoint of /L/ value if grayscale: 0 1 if Lab: low endpoint of /a/ chrominance value if grayscale: 0 1 if Lab: high endpoint of /a/ chrominance value if grayscale: 0 1 if Lab: low endpoint of /b/ chrominance value if grayscale: low endpoint of gray range 1 if Lab: high endpoint of /b/ chrominance value if grayscale: high endpoint of gray range /Replace color transform settings// / Length Description 2 Hue change. Short integer from -100...100. 2 Saturation change. Short integer from -100...100. 2 Lightness change Short integer from -100...100. . Selective Color Selective Color settings files are loaded and saved in Photoshop's Selective Color dialog.// /Selective color file types / OS Filetype/extension Mac OS /8BSV/ Windows /.ASV/ /Selective color file format / Length Description 2 Version ( = 1) 2 Correction method.. 0 = Apply color correction in relative mode; 1 = Apply color correction in absolute mode. 80 Ten eight-byte plate correction records, described in See Plate correction structure . The first record is ignored by Photoshop and is reserved for future use. It should be set to all zeroes. The rest of the records apply to specific areas of colors or lightness values in the image, in the following order: reds, yellows, greens, cyans, blues, magentas, whites, neutrals, blacks. /Plate correction structure / Length Description 2 Amount of cyan correction. Short integer from -100...100. 2 Amount of magenta correction. Short integer from -100...100. 2 Amount of yellow correction. Short integer from -100...100. 2 Amount of black correction. Short integer from -100...100. Separation Tables This format has been superseded by ICC profiles. See / ICC1v42_2006-05.pdf/ for details. Separation Table files are accessed in the Separation Tables dialog / (load only)/ .// /Separation table file types / OS Filetype/extension Mac OS /8BST/ Windows /.AST/ Format: If the size of the file is /33 * 33 * 33 * 4/ , then the file consists only of a Lab->CMYK table as currently documented.// If the size of the file is ( /33 * 33 * 33 + 256 ) * 3/ , then the file consists only of a CMYK->Lab table as currently documented. Otherwise, the file has the format listed in See Separation table file format . /Separation table file format / Length Description 2 Version ( = 300) 1 Boolean. True if contains Lab->CMYK table. 1 Boolean. True if contains CMYK->Lab table. 33*33*33*4 If file contains Lab->CMYK table, this section contains CMYK colors for 33*33*33 Lab colors. The CMYK colors are written in interleaved order, one byte each ink. 0 = 100%, 255 = 0%. See See Generating Lab source colors below. (33*33*33 +256)*3 If file contains CMYK->Lab table, this section contains Lab colors for 33*33*33+256 CMYK colors. The Lab colors are written in interleaved order, one byte per component. See See Generating CMYK source colors below.// 1 Boolean. True if gamut table follows. 1 If entry above is /false/ , this byte will not be present. If /true,/ this byte should be set to 1 for compatibility. (((33*33*33L)+7)>>3) if gamut table present, zero otherwise Gamut table, if present. The gamut table is a bit table indexed in the same way as the Lab->CMYK table with the high bit of the first byte at index 0. See See Testing for bits in the gamut table below. Generating Lab source colors The Lab colors that are the source colors can be generated from the / Lab->CMYK/ table with the following routine: for (i = 0; i < 33; i++) for (j = 0; j < 33; j++) for (n = 0; n < 33; n++) { L = Min (i * 8, 255); a = Min (j * 8, 255); b = Min (n * 8, 255); } Generating CMYK source colors The CMYK colors that are the source colors can be generated from the / CMYK->Lab/ table with the following routine: for (i = 0; i < 33; i++) for (j = 0; j < 33; j++) for (n = 0; n < 33; n++) { c = Min (i * 8, 255); m = Min (j * 8, 255); y = Min (n * 8, 255); k = 255; } for (i = 0; i < 256; i++) { c = 255; m = 255; y = 255; k = i; } Testing for bits in the gamut table To test the bit at /bitIndex/ , use table: ([bitIndex >> 3] & (0x0080 >> (bitIndex & 0x07))) != 0. /bitIndex/ itself is calculated in the same way you would calculate an index into the /Lab->CMYK/ table. A result of /1/ indicates that the color is in gamut and /0/ indicates that it is out of gamut. Transfer Function Transfer Function settings files are accessed /(load only) /in Photoshop's Duotone Curve dialog from within Duotone Options and Transfer Function dialogs (available from /Edit > Print with Preview/ in Photoshop 7, or /Page Setup/ or /Print Options/ in previous versions).Transfer Function files can also be loaded into any of Photoshop's curves dialogs, such as the Curves color adjustment dialog.// /Transfer function file types / OS Filetype/extension Mac OS /8BTF/ Windows /.ATF/ /Transfer function file format / Length Description 2 Version ( = 4) 112 (= 28*4) Four transfer functions , described in See Transfer function structure . The file always contains four functions. When writing the printer transfer functions for grayscale images, for instance, Photoshop writes four copies of the single transfer function specified in the user interface. /Transfer function structure / Length Description 26 Curve. Array of 13 short integers from 0...1000 representing 0.0...100.0. All but the first and last value may be -1, representing no point on the curve. Any curves beyond the last plate should be equal to the /NULL/ curve. A /NULL/ transfer curve looks like this: 0, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1000. 2 Boolean. 0 = Let printer supply curve; 1 = Override printer's default transfer curve.