Strings in ADOBE.TXT
With the permission of Adobe, this chapter is excerpted from:
Adobe Photoshop 3.0.4
Software Development Kit
Revised: 16 July 1995
Adobe Photoshop 3.0.4 Software Development Kit
Copyright 1991-95 Adobe Systems Incorporated. All rights reserved.
Portions Copyright 1990-91 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, Adobe Premiere, Adobe Photoshop, Adobe Illustrator, Adobe Type
Manager, ATM and PostScript are trademarks of Adobe Systems Incorporated
that may be registered in certain jurisdictions. Macintosh and Apple are
registered trademarks, and Mac OS is a trademark of Apple Computer, Inc.
Microsoft, Windows are registered trademarks of Microsoft Corporation. All
other products or name brands are trademarks of their respective holders.
Most of the material for this document was derived from earlier works by
Thomas Knoll, Mark Hamburg and Zalman Stern. Additional contributions came
from David Corboy, Kevin Johnston, Sean Parent and Seetha Naray-anan. It
was then compiled and edited by Dave Wise and Paul Ferguson.
Version History
7 November 1994
David J. Wise
First draft
15 January 1995
David J. Wise
First release
8 February 1995
Seetharaman Narayanan
MS-Windows modifications
16 July 1995
Paul D. Ferguson
Reformatted and updated
for Photoshop 3.0.4
Chapter 10
Document File Formats
Adobe Photoshop saves a user's document in one of several formats, which
are listed under the pop-up menu in the
dialog. This chapter
doccuments these standard formats.
The formats discussed in this chapter include Photoshop 3.0 native format,
Photoshop EPS format, Filmstrip format, and TIFF format.
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).
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 an image, such as pen tool paths.
(They are referred to as resource data 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 table 10-1.
Table 10-1: Image resource block
Description
OSType
Photoshop always uses its signature, '8BIM'
int16
Unique identifier (see table 10-2).
PString
Namel
A pascal string, padded to make size even
(a null name consists of two bytes of 0)
int32
Size
Actual size of resource data. This does not
include the Type, ID, Name, or Size fields.
Variable
Resource data, padded to make size even
Image resources use several standard ID numbers, as shown in table 10-2.
Not all file formats use all ID's. Some information may be stored in
other sections of the file.
Table 10-2: Image resoure ID's
Description
0x03E8 (1000)
Obsolete-Photoshop 2.0 only. Contains five int16
values: number of channels, rows, columns, depth, and mode.
0x03E9 (1001)
Optional. Macintosh print manager print info record.
0x03EB (1003)
Obsolete-Photoshop 2.0 only. Contains the indexed color table.
0x03ED (1005)
Resolution information. See appendix A for description
of the ResolutionInfo structure.
0x03EE (1006)
Names of the alpha channels as a series of Pascal strings.
0x03EF (1007)
Display information for each channel. See appendix A
for a description of the DisplayInfo structure.
0x03F0 (1008)
Optional. The caption as a Pascal string.
0x03F1 (1009)
Border information. Contains a Fixed number for the
border width, and an int16 for border units (1=inches,
2=cm, 3=points, 4=picas, 5=columns).
0x03F2 (1010)
Background color. See the Colors file information in
chapter 11.
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.
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 path resource format later
in this chapter.
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. This contains the File Info... information.
0x0405 (1029)
Image mode for raw format files.
0x0406 (1030)
JPEG quality. Private.
0x07D0
0x0BB6 (2000
2998)
Path Information (saved paths)
0x0BB7 (2999)
Name of clipping path
0x2710 (10000)
Print flags information. 2 bytes version (= 1),
1 byte center crop marks, 1 byte (always zero),
4 bytes bleed width value, 2 bytes bleed width scale.
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,
and 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 2999. 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.
The path format returned by GetProperty ( ) call is identical to
what is described below. Refer to the 'Paths To Illustrator' 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.
On Intel processors (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 data record it is. Under Windows, you
should swap the bytes before accessing it as a short (int16).
Table 10-3: Path data record types
Selector
Description
Closed subpath length record
Closed subpath Bezier knot, linked
Closed subpath Bezier knot, unlinked
Open subpath length record
Open subpath Bezier knot, linked
Open subpath Bezier knot, unlinked
Path fill rule record
Clipboard 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 all zeroes which indicates that paths use even/odd rule.
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:
(1) the control point for the Bezier segment preceding the knot,
(2) the anchor point for the knot, and
(3) the control point for the Bezier segment leaving the knot.
Linked knots have their control points linked; editing one point
edits the other one 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.
Photoshop 3.0 files
Macintosh file type: '8BPS'
Windows file extension:.PSD
This is the native file format for Adobe Photoshop 3.0.
It supports storing all layer information.
Photoshop 3.0 files under Windows
All data is stored in big endian byte order; under Windows you
must byte swap short and long integers when reading or writing.
Photoshop 3.0 files under Mac OS
For cross-platform compatibility, all information needed by
Adobe Photoshop 3.0 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 Adobe Fetch, a 'pnot' 0 resource 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 a 'STR#' 128 resource and the caption text
is stored in a 'TEXT' 128 resource. For more information on the format
of these resources see Inside Macintosh: QuickTime Components and the
Adobe Fetch Awareness Developer's Toolkit.
All of the data from Photoshop's File Info dialog is stored in
an 'ANPA' 10000 resource. The data in this resource is stored as
an IPTC-NAA record 2 and should be readable by various tools from
Iron Mike. For more information on the format of this resource contact:
IPTC-NAA Digital Newsphoto Parameter Record
Newspaper Association of America
The Newspaper Center
11600 Sunrise Valley Drive
Reston VA 20091
Photoshop also creates 'icl8' -16455 and 'ICN#' -16455 resources
containing thumbnail images which will be shown in the Finder.
Photoshop 3.0 file format
The file format for Photoshop 3.0 is divided into five major parts.
-----------------------------
File Header
-----------------------------
Color Mode Data
-----------------------------
Image Resources
-----------------------------
Layer and Mask Information
-----------------------------
Image Data
-----------------------------
The file header is 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.
File header section
The file header contains the basic properties of the image.
Table 10-4: File header
Length
Name
Description
4 bytes
Signature
Always equal to '8BPS'. Do not try to
read the file if the signature does not
match this value.
2 bytes
Version
Always equal to 1. Do not try to
read the file if the version does
not match this value.
6 bytes
Reserved
Must be zero.
2 bytes
Channels
The number of channels in the image,
including any alpha channels. Supported
range is 1 to 24.
4 bytes
Rows
The height of the image in pixels.
Supported range is 1 to 30,000.
4 bytes
Columns
The width of the image in pixels.
Supported range is 1 to 30,000.
2 bytes
Depth
The number of bits per channel.
Supported values are 1, 8, and 16.
2 bytes
Mode
The color mode of the file.
Supported values are:
Bitmap = 0
Grayscale = 1
Indexed Color = 2
RGB Color = 3
CMYK Color = 4
Multichannel = 7
Duotone = 8
Lab Color = 9
Color mode data section
Only indexed color and duotone have color mode data. For all other
modes, this section is just 4 bytes: the length field, which is set to zero.
For indexed color images, the length will be equal to 768, and the
color data will contain the color table for the image, in non-interleaved
order.
For duotone images, the color data will contain the duotone specification,
the format of which is not documented. Other applications that read
Photoshop files can treat a duotone image as a grayscale image,
and just preserve the contents of the duotone information when reading
and writing the file.
Table 10-5: Color mode data
Length
Name
Description
4 bytes
Length
The length of the following color data.
Variable
Color data
The color data.
Image resources section
The third section of the file contains image resources. As with
the color mode data, the section is indicated by a length field
followed by the data. The image resources in this data area are
described in detail earlier in this chapter.
Table 10-6: Image resources
Length
Name
Description
4 bytes
Length
Length of image resource section.
Variable
Resources
Image resources.
Layer and mask information section
The fourth section contains information about Photoshop 3.0 layers
and masks. The formats of these records are discussed later in this
chapter. If there are no layers or masks, this
section is just 4 bytes: the length field, which is set to zero.
Table 10-7: Layer and mask information
Length
Name
Description
4 bytes
Length
Length of the miscellaneous information
section.
Variable
Layers
Layer info. See table 10-10.
Variable
Masks
One or more layer mask info structures.
See table 10-13.
Image data section
The image pixel data is the last section of a Photoshop
3.0 file. Image data is stored in planar order, first all the red
data, then all the green data, etc. Each plane is stored in
scanline order, with no pad bytes.
If the compression code is 0, the image data is just the raw image data.
If the compression code is 1, 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.
Table 10-8: Image data
Length
Name
Description
2 bytes
Compression
Compression method.
Raw data = 0, RLE compressed = 1.
Variable
Data
The image data.
Layer and mask records
Information about each layer and mask in a document is stored in the fourth
section of the file. The complete, merged image data is not stored here; it
resides in the last section of the file.
The first part of this section of the file contains layer information,
which is divided into layer structures and layer pixel data, as shown
in table 10-9. The second part of this section contains layer mask
data, which is described in table 10-16.
Table 10-9: Layer info section
Length
Name
Description
4 bytes
Length
Length of the layers info section, rounded
up to a multiple of 2.
Variable
Layers structure Data about each layer in the document.
See table 10-10.
Variable
Pixel data
Channel image data for each channel in
the order listed in the layers structure
section. See table 10-15.
Table 10-10: Layer structure
Length
Name
Description
2 bytes
Count
Number of layers. If <0, then number of
layers is absolute value, and the first
alpha channel contains the transparency
data for the merged result.
Variable
Layer
Information about each layer (table 10-11).
Table 10-11: Layer records
Length
Name
Description
4 bytes
Layer top
The rectangle containing the contents
of the layer.
4 bytes
Layer left
4 bytes
Layer bottom
4 bytes
Layer right
2 bytes
Number channels The number of channels in the layer.
Variable
Channel length info
Channel information. This contains
a six byte record for each channel.
See table 10-12.
4 bytes
Blend mode signature
Always '8BIM'.
4 bytes
Blend mode key
'norm' = normal
'dark' = darken
'lite' = lighten
'hue ' = hue
'sat ' = saturation
'colr' = color
'lum ' = luminosity
'mul ' = multiply
'scrn' = screen
'diss' = dissolve
'over' = overlay
'hLit' = hard light
'sLit' = soft light
'diff' = difference
1 byte
Opacity
0 = transparent ... 255 = opaque
1 byte
Clipping
0 = base, 1 = non-base
1 byte
Flags
bit0: transparency protected
bit1: visible
1 byte
(filler)
(zero)
4 bytes
Extra data size Length of the extra data field. This is
the total length of the next five fields.
24 bytes, or 4 bytes if no layer mask.
Layer mask data
See table 10-13.
Variable
Layer blending ranges i
See table 10-14.
Variable
Layer name
Pascal string, padded to a multiple of 4 bytes.
Table 10-12: Channel length info
Length
Name
Description
2 bytes
Channel ID
0 = red, 1 = green, etc.
-1 = transparency mask
-2 = user supplied layer mask
4 bytes
Length
Length of following channel data.
Table 10-13: Layer mask data
Length
Name
Description
4 bytes
Size
Size of layer mask data. This will be
either 0x14, or zero (in which case the
following fields are not present).
4 bytes
Rectangle enclosing layer mask.
4 bytes
4 bytes
Bottom
4 bytes
Right
1 byte
Default color
0 or 255
1 byte
Flags
bit 0: position relative to layer
bit 1: layer mask disabled
bit 2: invert layer mask when blending
2 bytes
Padding
Zeros
Table 10-14: Layer blending ranges data
Length
Name
Description
4 bytes
Length
Length of layer blending ranges data
4 bytes
Composite gray blend source
Contains 2 black values followed by 2
white values.
Present but irrelevant for Lab & Grayscale.
4 bytes
Composite gray blend destination
Destination Range
4 bytes
First channel source range
4 bytes
First channel destination range
4 bytes
Second channel source range
4 bytes
Second channel destination range
... ... ...
4 bytes
Nth channel source range
4 bytes
Nth channel destination range
Table 10-15: Channel image data
Length
Name
Description
2 bytes
Compression
0 = Raw Data, 1 = RLE compressed.
Variable
Image data
If the compression code is 0, the image data
is just the raw image data calculated as
((Layer Bottom - Layer Top) *
(Layer Right - Layer Left)). If the
compression code is 1, the image data
starts with the byte counts for all the
scan lines in the channel (Layer Bottom -
Layer Top), 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.
If the data since the Layers Size is odd,
a pad byte will be inserted.
Table 10-16: Layer mask data
Length
Name
Description
2 bytes
Overlay color space
8 bytes
Color components
4 * 2 byte color components
2 bytes
Opacity
0 = transparent, 100 = opaque.
1 byte
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.
1 byte
(filler)
(zero)
Photoshop EPS files
Photoshop 3.0 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: <length> <hex data>
<length> is the length of the image resource data.
<hex data> is the 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: <columns> <rows> <depth> <mode> <pad channels> <block size>
<binary/hex> "<data start>"
<columns> is the width of the image in pixels.
<rows> is the height of the image in pixels.
<depth> is the number of bits per channel. Must be 1 or 8.
<mode> is the image mode. 1 for bitmap and gray scale images (determined by
depth), 2 for Lab images, 3 for RGB images, and 4 for CMYK images.
<pad channels> is the number of other channels stored in the file, which are
ignored when reading. (Photoshop uses this to include a gray scale image that
is printed on non
-olor PostScript printers).
<block size> is the number of bytes per row per channel. This will be
equal to (<columns> * <depth> + 7) / 8 if the data is stored in
line-interleave format (or if there is only one channel), or equal to
1 of the data is interleaved.
<binary/hex> is 1 if the data is in binary format, and 2 if the data
is in hex format.
<data start> contains the entire PostScript line immediately preceding the
image data. (This entire line should not occur elsewhere in the PostScript
header code, but it may occur at part of a line.)
Filmstrip files
Adobe Premiere 2.0 supports the filmstrip file format. Premiere users can
export any video clip as a filmstrip. Refer to the Adobe Premiere User
Guide for more information.
Adobe Photoshop 3.0 supports the filmstrip file type to allow each frame
to be individually painted. The filmstrip file format is fairly simple,
and is described in this section.
A filmstrip consists of a sequence of equal sized 32
bit images, known as
frames. The channel order in the file is Red, Green, Blue, Alpha.
After each frame is an arbitrarily sized leader area, in which any type of
information may be embedded. Adobe Premiere puts the timecode and frame
number for the frame in this area. This area is ignored by Premiere
when the file is read.
Following all the frames is a 16 row trailer frame (it has the same width
as the other frames). Adobe Premiere writes a yellow and black diagonal
pattern in this area. The lower right corner of this area is
actually an information record that exists at the very end of
the file. This record is located by seeking to the end
of the file minus the size of the record, then reading the record
and verifying the signature field that it contains.
// Definition for filmstrip info record
typedef struct {
long signature; // 'Rand'
long numFrames; // number of frames in file
short packing; // packing method
short reserved; // reserved, should be 0
short width; // image width
short height; // image height
short leading; // horiz gap between frames
short framesPerSec;// frame rate
char spare[16]; // some spare data.
} FilmStripRec, **FilmStripHand;
Table 10-17: FilmStripRec structure
Type
Field
Description
long
signature
This field must be set to the code 'Rand'
and is used to verify the validity of the
record.
long
numFrames
This is the total number of frames in the file.
short
packing
This is the packing method used, currently
only a value of 0 is defined, for no packing.
short
width
The width of each image, in pixels.
short
height
The height of each image, in pixels.
short
leading
The height of the leading areas, in pixels.
short
framesPerSec
The rate at which the frames should be played.
To locate the filmstrip info record, seek to the end of the file minus
(sizeof(FilmStripRec)), then read in the FilmStrip record. Check the signature
field for the code 'Rand' to test for validity.
To locate the data for a particular frame, seek to (frame * width *
(height+leading) * 4), then read (width * height * 4) bytes.
If the data is being placed into a GWorld (Mac OS), the channels must
be rearranged from Red-Green-Blue-Alpha to Alpha-Red-Green-Blue.
To write a FilmStrip file, write each frame sequentially into the file,
including the leading areas. Then write a block of ((width *
(height+leading) * 4) - sizeof(FilmStripRec)) bytes. Finally, fill in
and write the FilmStrip record to the file.
Note: The packing field should currently be zero. In the future
packing methods may be defined for filmstrips, so any software which
reads filmstrips should examine this field before opening the file.
TIFF files
The same image resources information found in Photoshop 3.0 files are stored
in TIFF files under tag number 34377 (see Image Resource Blocks and Image
Resources earlier in this chapter).
For TIFF files the caption data is stored in an image description tag
270 and all the information is stored as an IPTC
NAA record 2 in tag
33723. The tag number was chosen by inspecting files written by
Iron Mike software, and is supposed to be defined in a Rich TIFF
specification. The tag is also specified in:
NSK TIFF
The Japan Newspaper Publishers & Editors Association
Nippon Press Center
Building 2-2-1 Uchlsaiwai-cho
Chiyoda-ku, Tokyo 100
For more information about the TIFF format see:
TIFF Revision 6.0
(206) 628-5693
In reading the files, the following order is used with information read
lower on the list replacing information read higher.
Image Description Tag (TIFF only)
IPTC-NAA Tag (TIFF only)
It is a bug that the TIFF information comes prior to the image resource
information on this list. This means that an edit to the TIFF info
will not be recognized unless the image resource information is removed.
The TIFF data may be moved to after the image resource information
in a future version of Photoshop.
Table 10-16 describes the standard TIFF tags and tag values that
Photoshop 3.0 is able to read and write.
TIFF files under Mac OS
For cross-platform compatibility, all TIFF information 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 Adobe Fetch, a 'pnot' 0 resource 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 a 'STR#' 128 resource and the caption text is stored in a 'TEXT'
128 resource. For more information on the format of these resources
see Inside Macintosh: QuickTime Components and the Adobe Fetch Awareness
Developer's Toolkit.
All of the data from Photoshop's File Info dialog is stored in an
'ANPA' 10000 resource. The TIFF file also contains a 'STR ' -16396 resource
that contains the string 'Adobe Photoshop' 3.0' which indicates the
application that created the TIFF file.
Photoshop also creates 'icl8' -16455 and 'ICN#' -16455 resources containing
thumbnail images which will be shown in the Finder.
10-18: TIFF Tags
Photoshop reads
Photoshop writes
First IFD in file
Only one IFD per file
NewSubFileType
Ignored
ImageWidth
1 to 30000
1 to 30000
ImageLength
1 to 30000
1 to 30000
BitsPerSample
1, 2, 4, 8, 16 (all same)
1, 8, 16
Compression
1, 2, 5, 32773
PhotometricInterpretation
0, 1, 2, 3, 5, 8 0
(1-bit), 1 (8-bit), 2, 3,5,8
FillOrder
ImageDescription Printing Caption
Printing Caption
StripOffsets
SamplesPerPixel 1 to 24
1 to 24
RowsPerStrip
Single strip if not compressed,
multiple strips if compressed.
StripByteCounts Required if compressed
XResolution
YResolution
Ignored (square pixels assumed)
PlanarConfiguration 1 or 2
ResolutionUnit
2 or 3
Predictor
1 or 2
1 or 2
ColorMap
TileWidth
TileLength
TileOffsets
TileByteCounts
Required if compressed
InkSet
DotRange
Yes, if CMYK
ExtraSamples
Ignored (except for count)
