-! Copyright (C) 2009 Doug Coleman.
+! Copyright (C) 2009 Doug Coleman, Keith Lazuka
! See http://factorcode.org/license.txt for BSD license.
-USING: images.testing ;
+USING: images.testing io.directories ;
IN: images.png.tests
-"vocab:images/testing/png/rgb.png" decode-test
-"vocab:images/testing/png/yin_yang.png" decode-test
+! Test files from PngSuite (http://www.libpng.org/pub/png/pngsuite.html)
+
+! The subset of the suite that should work given the current implementation.
+"vocab:images/testing/png" [
+ "basn2c08.png" decode-test
+ "basn6a08.png" decode-test
+ "f00n2c08.png" decode-test
+ "f01n2c08.png" decode-test
+ "f02n2c08.png" decode-test
+ "f03n2c08.png" decode-test
+ "f04n2c08.png" decode-test
+ "z00n2c08.png" decode-test
+ "z03n2c08.png" decode-test
+ "z06n2c08.png" decode-test
+ "z09n2c08.png" decode-test
+] with-directory
+
+! The current PNG decoder implementation is very limited,
+! so the entire test suite is not currently enabled.
+! "vocab:images/testing/png/suite" [
+! "basi0g01.png" decode-test
+! "basi0g02.png" decode-test
+! "basi0g04.png" decode-test
+! "basi0g08.png" decode-test
+! "basi0g16.png" decode-test
+! "basi2c08.png" decode-test
+! "basi2c16.png" decode-test
+! "basi3p01.png" decode-test
+! "basi3p02.png" decode-test
+! "basi3p04.png" decode-test
+! "basi3p08.png" decode-test
+! "basi4a08.png" decode-test
+! "basi4a16.png" decode-test
+! "basi6a08.png" decode-test
+! "basi6a16.png" decode-test
+! "basn0g01.png" decode-test
+! "basn0g02.png" decode-test
+! "basn0g04.png" decode-test
+! "basn0g08.png" decode-test
+! "basn0g16.png" decode-test
+! "basn2c08.png" decode-test
+! "basn2c16.png" decode-test
+! "basn3p01.png" decode-test
+! "basn3p02.png" decode-test
+! "basn3p04.png" decode-test
+! "basn3p08.png" decode-test
+! "basn4a08.png" decode-test
+! "basn4a16.png" decode-test
+! "basn6a08.png" decode-test
+! "basn6a16.png" decode-test
+! "bgai4a08.png" decode-test
+! "bgai4a16.png" decode-test
+! "bgan6a08.png" decode-test
+! "bgan6a16.png" decode-test
+! "bgbn4a08.png" decode-test
+! "bggn4a16.png" decode-test
+! "bgwn6a08.png" decode-test
+! "bgyn6a16.png" decode-test
+! "ccwn2c08.png" decode-test
+! "ccwn3p08.png" decode-test
+! "cdfn2c08.png" decode-test
+! "cdhn2c08.png" decode-test
+! "cdsn2c08.png" decode-test
+! "cdun2c08.png" decode-test
+! "ch1n3p04.png" decode-test
+! "ch2n3p08.png" decode-test
+! "cm0n0g04.png" decode-test
+! "cm7n0g04.png" decode-test
+! "cm9n0g04.png" decode-test
+! "cs3n2c16.png" decode-test
+! "cs3n3p08.png" decode-test
+! "cs5n2c08.png" decode-test
+! "cs5n3p08.png" decode-test
+! "cs8n2c08.png" decode-test
+! "cs8n3p08.png" decode-test
+! "ct0n0g04.png" decode-test
+! "ct1n0g04.png" decode-test
+! "ctzn0g04.png" decode-test
+! "f00n0g08.png" decode-test
+! "f00n2c08.png" decode-test
+! "f01n0g08.png" decode-test
+! "f01n2c08.png" decode-test
+! "f02n0g08.png" decode-test
+! "f02n2c08.png" decode-test
+! "f03n0g08.png" decode-test
+! "f03n2c08.png" decode-test
+! "f04n0g08.png" decode-test
+! "f04n2c08.png" decode-test
+! "g03n0g16.png" decode-test
+! "g03n2c08.png" decode-test
+! "g03n3p04.png" decode-test
+! "g04n0g16.png" decode-test
+! "g04n2c08.png" decode-test
+! "g04n3p04.png" decode-test
+! "g05n0g16.png" decode-test
+! "g05n2c08.png" decode-test
+! "g05n3p04.png" decode-test
+! "g07n0g16.png" decode-test
+! "g07n2c08.png" decode-test
+! "g07n3p04.png" decode-test
+! "g10n0g16.png" decode-test
+! "g10n2c08.png" decode-test
+! "g10n3p04.png" decode-test
+! "g25n0g16.png" decode-test
+! "g25n2c08.png" decode-test
+! "g25n3p04.png" decode-test
+! "oi1n0g16.png" decode-test
+! "oi1n2c16.png" decode-test
+! "oi2n0g16.png" decode-test
+! "oi2n2c16.png" decode-test
+! "oi4n0g16.png" decode-test
+! "oi4n2c16.png" decode-test
+! "oi9n0g16.png" decode-test
+! "oi9n2c16.png" decode-test
+! "pngsuite_logo.png" decode-test
+! "pp0n2c16.png" decode-test
+! "pp0n6a08.png" decode-test
+! "ps1n0g08.png" decode-test
+! "ps1n2c16.png" decode-test
+! "ps2n0g08.png" decode-test
+! "ps2n2c16.png" decode-test
+! "s01i3p01.png" decode-test
+! "s01n3p01.png" decode-test
+! "s02i3p01.png" decode-test
+! "s02n3p01.png" decode-test
+! "s03i3p01.png" decode-test
+! "s03n3p01.png" decode-test
+! "s04i3p01.png" decode-test
+! "s04n3p01.png" decode-test
+! "s05i3p02.png" decode-test
+! "s05n3p02.png" decode-test
+! "s06i3p02.png" decode-test
+! "s06n3p02.png" decode-test
+! "s07i3p02.png" decode-test
+! "s07n3p02.png" decode-test
+! "s08i3p02.png" decode-test
+! "s08n3p02.png" decode-test
+! "s09i3p02.png" decode-test
+! "s09n3p02.png" decode-test
+! "s32i3p04.png" decode-test
+! "s32n3p04.png" decode-test
+! "s33i3p04.png" decode-test
+! "s33n3p04.png" decode-test
+! "s34i3p04.png" decode-test
+! "s34n3p04.png" decode-test
+! "s35i3p04.png" decode-test
+! "s35n3p04.png" decode-test
+! "s36i3p04.png" decode-test
+! "s36n3p04.png" decode-test
+! "s37i3p04.png" decode-test
+! "s37n3p04.png" decode-test
+! "s38i3p04.png" decode-test
+! "s38n3p04.png" decode-test
+! "s39i3p04.png" decode-test
+! "s39n3p04.png" decode-test
+! "s40i3p04.png" decode-test
+! "s40n3p04.png" decode-test
+! "tbbn1g04.png" decode-test
+! "tbbn2c16.png" decode-test
+! "tbbn3p08.png" decode-test
+! "tbgn2c16.png" decode-test
+! "tbgn3p08.png" decode-test
+! "tbrn2c08.png" decode-test
+! "tbwn1g16.png" decode-test
+! "tbwn3p08.png" decode-test
+! "tbyn3p08.png" decode-test
+! "tp0n1g08.png" decode-test
+! "tp0n2c08.png" decode-test
+! "tp0n3p08.png" decode-test
+! "tp1n3p08.png" decode-test
+! "x00n0g01.png" decode-test
+! "xcrn0g04.png" decode-test
+! "xlfn0g04.png" decode-test
+! "z00n2c08.png" decode-test
+! "z03n2c08.png" decode-test
+! "z06n2c08.png" decode-test
+! "z09n2c08.png" decode-test
+! ] with-directory
--- /dev/null
+ PNGSUITE
+----------------
+
+ testset for PNG-(de)coders
+ created by Willem van Schaik
+------------------------------------
+
+This is a collection of graphics images created to test the png applications
+like viewers, converters and editors. All (as far as that is possible)
+formats supported by the PNG standard are represented.
+
+
+1. INTRODUCTION
+--------------------
+
+1.1 PNG capabilities
+------------------------
+
+Supported color-types are:
+
+ - grayscale
+ - grayscale + alpha-channel
+ - color palettes
+ - rgb
+ - rgb + alpha-channel
+
+Allowed bitdepths are depending on the color-type, but are in the range
+of 1-bit (grayscale, which is b&w) upto 16-bits.
+
+Special features are:
+
+ - interlacing (Adam-7)
+ - gamma-support
+ - transparency (a poor-man's alpha solution)
+
+
+1.2 File naming
+-------------------
+
+Where possible, the testfiles are 32x32 bits icons. This results in a still
+reasonable size of the suite even with a large number of tests. The name
+of each test-file reflects thetype in the following way:
+
+ g04i2c08.png
+ || |||+---- bit-depth
+ || ||+----- color-type (descriptive)
+ || |+------ color-type (numerical)
+ || +------- interlaced or non-interlaced
+ |+--------- parameter of test (in this case gamma-value)
+ +---------- test feature (in this case gamma)
+
+
+1.3 PNG formats
+-------------------
+
+color-type:
+ 0g - grayscale
+ 2c - rgb color
+ 3p - paletted
+ 4a - grayscale + alpha channel
+ 6a - rgb color + alpha channel
+
+bit-depth:
+ 01 - with color-type 0, 3
+ 02 - with color-type 0, 3
+ 04 - with color-type 0, 3
+ 08 - with color-type 0, 2, 3, 4, 6
+ 16 - with color-type 0, 2, 4, 6
+
+interlacing:
+ n - non-interlaced
+ i - interlaced
+
+
+2. THE TESTS
+-----------------
+
+2.1 Sizes
+-------------
+
+These tests are there to check if your software handles pictures well, with
+picture sizes that are not a multiple of 8. This is particularly important
+with Adam-7 type interlacing. In the same way these tests check if pictures
+size 1x1 and similar are ok.
+
+ s01 - 1x1 pixel picture
+ s02 - 2x2 pixel picture
+ s03 - 3x3 pixel picture
+ s04 - 4x4 pixel picture
+ s05 - 5x5 pixel picture
+ s06 - 6x6 pixel picture
+ s07 - 7x7 pixel picture
+ s08 - 8x8 pixel picture
+ s09 - 9x9 pixel picture
+ s32 - 32x32 pixel picture
+ s33 - 33x33 pixel picture
+ s34 - 34x34 pixel picture
+ s35 - 35x35 pixel picture
+ s36 - 36x36 pixel picture
+ s37 - 37x37 pixel picture
+ s38 - 38x38 pixel picture
+ s39 - 39x39 pixel picture
+ s40 - 40x40 pixel picture
+
+
+2.2 Background
+------------------
+
+When the PNG file contains a background chunck, this should be used for
+pictures with alpha-channel or pictures with a transparency chunck. For
+pictures without this background-chunk, but with alpha, this testset
+assumes a black background.
+
+For the images in this test, the left-side should be 100% the background
+color, where moving to the right the color should gradually become the
+image pattern.
+
+ bga - alpha + no background
+ bgw - alpha + white background
+ bgg - alpha + gray background
+ bgb - alpha + black background
+ bgy - alpha + yellow background
+
+
+2.3 Transparency
+--------------------
+
+Transparency should be used together with a background chunk. To test the
+combination of the two the latter 4 tests are there. How to handle pictures
+with transparancy, but without a background, opinions can differ. Here we
+use black, but especially in the case of paletted images, the normal color
+would maybe even be better.
+
+ tp0 - not transparent for reference
+ tp1 - transparent, but no background chunk
+ tbw - transparent + white background
+ tbg - transparent + gray background
+ tbb - transparent + black background
+ tby - transparent + yellow background
+
+
+2.4 Gamma
+-------------
+
+To test if your viewer handles gamma-correction, 6 testfiles are available.
+They contain corrected color-ramps and a corresponding gamma-chunk with the
+file-gamma value. These are created in such a way that when the viewer does
+the gamma correction right, all 6 should be displayed identical.
+
+If they are different, probably the gamma correction is omitted. In that
+case, have a look at the two right coloumns in the 6 pictures. The image
+where those two look the same (when looked from far) reflects the gamma of
+your system. However, because of the limited size of the image, you should
+do more elaborate tests to determine your display gamma.
+
+ g03 - file-gamma = 0.35, for display with gamma = 2.8
+ g04 - file-gamma = 0.45, for display with gamma = 2.2 (PC)
+ g05 - file-gamma = 0.55, for display with gamma = 1.8 (Mac)
+ g07 - file-gamma = 0.70, for display with gamma = 1.4
+ g10 - file-gamma = 1.00, for display with gamma = 1.0 (NeXT)
+ g25 - file-gamma = 2.50, for display with gamma = 0.4
+
+
+2.5 Filtering
+-----------------
+
+PNG uses file-filtering, for optimal compression. Normally the type is of
+filtering is adjusted to the contents of the picture, but here each file
+has the same picture, with a different filtering.
+
+ f0 - no filtering
+ f1 - sub filtering
+ f2 - up filtering
+ f3 - average filtering
+ f4 - paeth filtering
+
+
+2.6 Additional palettes
+---------------------------
+
+Besides the normal use of paletted images, palette chunks can in combination
+with true-color (and other) images also be used to select color lookup-tables
+when the video system is of limited capabilities. The suggested palette chunk
+is specially created for this purpose.
+
+ pp - normal palette chunk
+ ps - suggested palette chunk
+
+
+2.7 Ancillary chunks (under construction)
+------------------------
+
+To test the correct decoding of ancillary chunks, these test-files contain
+one or more examples of these chunkcs. Depending on the type of chunk, a
+number of typical values are selected to test. Unluckily, the testset can
+not contain all combinations, because that would be an endless set.
+
+The significant bits are used in files with the next higher bit-depth. They
+indicate howmany bits are valid.
+
+ cs3 - 3 significant bits
+ cs5 - 5 significant bits
+ cs8 - 8 significant bits (reference)
+ cs3 - 13 significant bits
+
+For the physical pixel dimensions, the result of each decoding should be
+a sqare picture. The first (cdf) image is an example of flat (horizontal)
+pixels, where the pHYS chunk (x is 1 per unit, y = 4 per unit) must take
+care of the correction. The second is just the other way round. The last
+example uses the unit specifier, for 1000 pixels per meter. This should
+result in a picture of 3.2 cm square.
+
+ cdf - physical pixel dimensions, 8x32 flat pixels
+ cdh - physical pixel dimensions, 32x8 high pixels
+ cds - physical pixel dimensions, 8x8 square pixels
+ cdu - physical pixel dimensions, with unit-specifier
+
+ ccw - primary chromaticities and white point
+
+ ch1 - histogram 15 colors
+ ch2 - histogram 256 colors
+
+ cm7 - modification time, 01-jan-1970
+ cm9 - modification time, 31-dec-1999
+ cm0 - modification time, 01-jan-2000
+
+In the textual chunk, a number of the standard, and some non-standard
+text items are included.
+
+ ct0 - no textual data
+ ct1 - with textual data
+ ctz - with compressed textual data
+
+
+2.8 Chunk ordering (still under construction)
+----------------------
+
+These testfiles will test the obligatory ordering relations between various
+chunk types (not yet) as well as the number of data chunks used for the image.
+
+ oi1 - mother image with 1 idat-chunk
+ oi2 - image with 2 idat-chunks
+ oi4 - image with 4 unequal sized idat-chunks
+ oi9 - all idat-chunks of length one
+
+
+2.9 Compression level
+-------------------------
+
+Here you will find a set of images compressed by zlib, ranging from level 0
+for no compression at maximum speed upto level 9 for maximum compression.
+
+ z00 - zlib compression level 0 - none
+ z03 - zlib compression level 3
+ z06 - zlib compression level 6 - default
+ z09 - zlib compression level 9 - maximum
+
+
+2.10 Corrupted files (under construction)
+-----------------------
+
+All these files are illegal. When decoding they should generate appropriate
+error-messages.
+
+ x00 - empty IDAT chunk
+ xcr - added cr bytes
+ xlf - added lf bytes
+ xc0 - color type 0
+ xc9 - color type 9
+ xd0 - bit-depth 0
+ xd3 - bit-depth 3
+ xd9 - bit-depth 99
+ xcs - incorrect IDAT checksum
+
+
+3. TEST FILES
+------------------
+
+For each of the tests listed above, one or more test-files are created. A
+selection is made (for each test) for the color-type and bitdepth to be used
+for the tests. Further for a number of tests, both a non-interlaced as well
+as an interlaced version is available.
+
+
+3.1 Basic format test files (non-interlaced)
+------------------------------------------------
+
+ basn0g01 - black & white
+ basn0g02 - 2 bit (4 level) grayscale
+ basn0g04 - 4 bit (16 level) grayscale
+ basn0g08 - 8 bit (256 level) grayscale
+ basn0g16 - 16 bit (64k level) grayscale
+ basn2c08 - 3x8 bits rgb color
+ basn2c16 - 3x16 bits rgb color
+ basn3p01 - 1 bit (2 color) paletted
+ basn3p02 - 2 bit (4 color) paletted
+ basn3p04 - 4 bit (16 color) paletted
+ basn3p08 - 8 bit (256 color) paletted
+ basn4a08 - 8 bit grayscale + 8 bit alpha-channel
+ basn4a16 - 16 bit grayscale + 16 bit alpha-channel
+ basn6a08 - 3x8 bits rgb color + 8 bit alpha-channel
+ basn6a16 - 3x16 bits rgb color + 16 bit alpha-channel
+
+
+3.2 Basic format test files (Adam-7 interlaced)
+---------------------------------------------------
+
+ basi0g01 - black & white
+ basi0g02 - 2 bit (4 level) grayscale
+ basi0g04 - 4 bit (16 level) grayscale
+ basi0g08 - 8 bit (256 level) grayscale
+ basi0g16 - 16 bit (64k level) grayscale
+ basi2c08 - 3x8 bits rgb color
+ basi2c16 - 3x16 bits rgb color
+ basi3p01 - 1 bit (2 color) paletted
+ basi3p02 - 2 bit (4 color) paletted
+ basi3p04 - 4 bit (16 color) paletted
+ basi3p08 - 8 bit (256 color) paletted
+ basi4a08 - 8 bit grayscale + 8 bit alpha-channel
+ basi4a16 - 16 bit grayscale + 16 bit alpha-channel
+ basi6a08 - 3x8 bits rgb color + 8 bit alpha-channel
+ basi6a16 - 3x16 bits rgb color + 16 bit alpha-channel
+
+
+3.3 Sizes test files
+-----------------------
+
+ s01n3p01 - 1x1 paletted file, no interlacing
+ s02n3p01 - 2x2 paletted file, no interlacing
+ s03n3p01 - 3x3 paletted file, no interlacing
+ s04n3p01 - 4x4 paletted file, no interlacing
+ s05n3p02 - 5x5 paletted file, no interlacing
+ s06n3p02 - 6x6 paletted file, no interlacing
+ s07n3p02 - 7x7 paletted file, no interlacing
+ s08n3p02 - 8x8 paletted file, no interlacing
+ s09n3p02 - 9x9 paletted file, no interlacing
+ s32n3p04 - 32x32 paletted file, no interlacing
+ s33n3p04 - 33x33 paletted file, no interlacing
+ s34n3p04 - 34x34 paletted file, no interlacing
+ s35n3p04 - 35x35 paletted file, no interlacing
+ s36n3p04 - 36x36 paletted file, no interlacing
+ s37n3p04 - 37x37 paletted file, no interlacing
+ s38n3p04 - 38x38 paletted file, no interlacing
+ s39n3p04 - 39x39 paletted file, no interlacing
+ s40n3p04 - 40x40 paletted file, no interlacing
+
+ s01i3p01 - 1x1 paletted file, interlaced
+ s02i3p01 - 2x2 paletted file, interlaced
+ s03i3p01 - 3x3 paletted file, interlaced
+ s04i3p01 - 4x4 paletted file, interlaced
+ s05i3p02 - 5x5 paletted file, interlaced
+ s06i3p02 - 6x6 paletted file, interlaced
+ s07i3p02 - 7x7 paletted file, interlaced
+ s08i3p02 - 8x8 paletted file, interlaced
+ s09i3p02 - 9x9 paletted file, interlaced
+ s32i3p04 - 32x32 paletted file, interlaced
+ s33i3p04 - 33x33 paletted file, interlaced
+ s34i3p04 - 34x34 paletted file, interlaced
+ s35i3p04 - 35x35 paletted file, interlaced
+ s36i3p04 - 36x36 paletted file, interlaced
+ s37i3p04 - 37x37 paletted file, interlaced
+ s38i3p04 - 38x38 paletted file, interlaced
+ s39i3p04 - 39x39 paletted file, interlaced
+ s40i3p04 - 40x40 paletted file, interlaced
+
+
+3.4 Background test files (with alpha)
+------------------------------------------
+
+ bgai4a08 - 8 bit grayscale, alpha, no background chunk, interlaced
+ bgai4a16 - 16 bit grayscale, alpha, no background chunk, interlaced
+ bgan6a08 - 3x8 bits rgb color, alpha, no background chunk
+ bgan6a16 - 3x16 bits rgb color, alpha, no background chunk
+
+ bgbn4a08 - 8 bit grayscale, alpha, black background chunk
+ bggn4a16 - 16 bit grayscale, alpha, gray background chunk
+ bgwn6a08 - 3x8 bits rgb color, alpha, white background chunk
+ bgyn6a16 - 3x16 bits rgb color, alpha, yellow background chunk
+
+
+3.5 Transparency (and background) test files
+------------------------------------------------
+
+ tp0n1g08 - not transparent for reference (logo on gray)
+ tbbn1g04 - transparent, black background chunk
+ tbwn1g16 - transparent, white background chunk
+ tp0n2c08 - not transparent for reference (logo on gray)
+ tbrn2c08 - transparent, red background chunk
+ tbgn2c16 - transparent, green background chunk
+ tbbn2c16 - transparent, blue background chunk
+ tp0n3p08 - not transparent for reference (logo on gray)
+ tp1n3p08 - transparent, but no background chunk
+ tbbn3p08 - transparent, black background chunk
+ tbgn3p08 - transparent, light-gray background chunk
+ tbwn3p08 - transparent, white background chunk
+ tbyn3p08 - transparent, yellow background chunk
+
+
+3.6 Gamma test files
+------------------------
+
+ g03n0g16 - grayscale, file-gamma = 0.35
+ g04n0g16 - grayscale, file-gamma = 0.45
+ g05n0g16 - grayscale, file-gamma = 0.55
+ g07n0g16 - grayscale, file-gamma = 0.70
+ g10n0g16 - grayscale, file-gamma = 1.00
+ g25n0g16 - grayscale, file-gamma = 2.50
+ g03n2c08 - color, file-gamma = 0.35
+ g04n2c08 - color, file-gamma = 0.45
+ g05n2c08 - color, file-gamma = 0.55
+ g07n2c08 - color, file-gamma = 0.70
+ g10n2c08 - color, file-gamma = 1.00
+ g25n2c08 - color, file-gamma = 2.50
+ g03n3p04 - paletted, file-gamma = 0.35
+ g04n3p04 - paletted, file-gamma = 0.45
+ g05n3p04 - paletted, file-gamma = 0.55
+ g07n3p04 - paletted, file-gamma = 0.70
+ g10n3p04 - paletted, file-gamma = 1.00
+ g25n3p04 - paletted, file-gamma = 2.50
+
+
+3.7 Filtering test files
+----------------------------
+
+ f00n0g08 - grayscale, no interlacing, filter-type 0
+ f01n0g08 - grayscale, no interlacing, filter-type 1
+ f02n0g08 - grayscale, no interlacing, filter-type 2
+ f03n0g08 - grayscale, no interlacing, filter-type 3
+ f04n0g08 - grayscale, no interlacing, filter-type 4
+ f00n2c08 - color, no interlacing, filter-type 0
+ f01n2c08 - color, no interlacing, filter-type 1
+ f02n2c08 - color, no interlacing, filter-type 2
+ f03n2c08 - color, no interlacing, filter-type 3
+ f04n2c08 - color, no interlacing, filter-type 4
+
+
+3.8 Additional palette chunk test files
+-------------------------------------------
+
+ pp0n2c16 - six-cube palette-chunk in true-color image
+ pp0n6a08 - six-cube palette-chunk in true-color+alpha image
+ ps1n0g08 - six-cube suggested palette (1 byte) in grayscale image
+ ps1n2c16 - six-cube suggested palette (1 byte) in true-color image
+ ps2n0g08 - six-cube suggested palette (2 bytes) in grayscale image
+ ps2n2c16 - six-cube suggested palette (2 bytes) in true-color image
+
+
+3.9 Ancillary chunks test files
+-----------------------------------
+
+ cs5n2c08 - color, 5 significant bits
+ cs8n2c08 - color, 8 significant bits (reference)
+ cs3n2c16 - color, 13 significant bits
+ cs3n3p08 - paletted, 3 significant bits
+ cs5n3p08 - paletted, 5 significant bits
+ cs8n3p08 - paletted, 8 significant bits (reference)
+
+ cdfn2c08 - physical pixel dimensions, 8x32 flat pixels
+ cdhn2c08 - physical pixel dimensions, 32x8 high pixels
+ cdsn2c08 - physical pixel dimensions, 8x8 square pixels
+ cdun2c08 - physical pixel dimensions, 1000 pixels per 1 meter
+
+ ccwn2c08 - chroma chunk w:0.3127,0.3290 r:0.64,0.33 g:0.30,0.60 b:0.15,0.06
+ ccwn3p08 - chroma chunk w:0.3127,0.3290 r:0.64,0.33 g:0.30,0.60 b:0.15,0.06
+
+ ch1n3p04 - histogram 15 colors
+ ch2n3p08 - histogram 256 colors
+
+ cm7n0g04 - modification time, 01-jan-1970 00:00:00
+ cm9n0g04 - modification time, 31-dec-1999 23:59:59
+ cm0n0g04 - modification time, 01-jan-2000 12:34:56
+
+ ct0n0g04 - no textual data
+ ct1n0g04 - with textual data
+ ctzn0g04 - with compressed textual data
+
+
+
+3.10 Chunk ordering
+----------------------
+
+ oi1n0g16 - grayscale mother image with 1 idat-chunk
+ oi2n0g16 - grayscale image with 2 idat-chunks
+ oi4n0g16 - grayscale image with 4 unequal sized idat-chunks
+ oi9n0g16 - grayscale image with all idat-chunks length one
+ oi1n2c16 - color mother image with 1 idat-chunk
+ oi2n2c16 - color image with 2 idat-chunks
+ oi4n2c16 - color image with 4 unequal sized idat-chunks
+ oi9n2c16 - color image with all idat-chunks length one
+
+
+
+3.11 Compression level
+-------------------------
+
+ z00n2c08 - color, no interlacing, compression level 0 (none)
+ z03n2c08 - color, no interlacing, compression level 3
+ z06n2c08 - color, no interlacing, compression level 6 (default)
+ z09n2c08 - color, no interlacing, compression level 9 (maximum)
+
+
+
+3.12 Currupted files
+-----------------------
+
+ x00n0g01 - empty 0x0 grayscale file
+ xcrn0g04 - added cr bytes
+ xlfn0g04 - added lf bytes
+ xc0n0c08 - color type 0
+ xc9n0c08 - color type 9
+ xd0n2c00 - bit-depth 0
+ xd3n2c03 - bit-depth 3
+ xd9n2c99 - bit-depth 99
+ xcsn2c08 - incorrect IDAT checksum
+
+
+--------
+ (c) Willem van Schaik
+ willem@schaik.com
+ Singapore, October 1996
projects / factor.git / commitdiff
