README
1The *.png and README.original files in this directory are copied from
2libpng.org, specifically contrib/pngsuite/* in libpng 1.6.26.
3
4README.original gives the following license for those files:
5
6 Permission to use, copy, and distribute these images for any purpose
7 and without fee is hereby granted.
8
9The files basn0g01-30.png, basn0g02-29.png and basn0g04-31.png are in fact not
10part of pngsuite but were created from files in pngsuite. Their non-power-of-2
11sizes makes them useful for testing bit-depths smaller than a byte.
12
13basn3a08.png was generated from basn6a08.png using the pngnq tool, which
14converted it to the 8-bit paletted image with alpha values in tRNS chunk.
15
16The *.sng files in this directory were generated from the *.png files by the
17sng command-line tool and some hand editing. The files basn0g0{1,2,4}.sng and
18ftbbn0g0{1,2,4}.sng were actually generated by first converting the PNG to a
19bitdepth of 8 and then running sng on them. basn4a08.sng was generated from a
2016-bit rgba version of basn4a08.png rather than the original gray + alpha.
21
README.original
1
2pngsuite
3--------
4(c) Willem van Schaik, 1999
5
6Permission to use, copy, and distribute these images for any purpose and
7without fee is hereby granted.
8
9These 15 images are part of the much larger PngSuite test-set of
10images, available for developers of PNG supporting software. The
11complete set, available at http:/www.schaik.com/pngsuite/, contains
12a variety of images to test interlacing, gamma settings, ancillary
13chunks, etc.
14
15The images in this directory represent the basic PNG color-types:
16grayscale (1-16 bit deep), full color (8 or 16 bit), paletted
17(1-8 bit) and grayscale or color images with alpha channel. You
18can use them to test the proper functioning of PNG software.
19
20 filename depth type
21 ------------ ------ --------------
22 basn0g01.png 1-bit grayscale
23 basn0g02.png 2-bit grayscale
24 basn0g04.png 4-bit grayscale
25 basn0g08.png 8-bit grayscale
26 basn0g16.png 16-bit grayscale
27 basn2c08.png 8-bit truecolor
28 basn2c16.png 16-bit truecolor
29 basn3p01.png 1-bit paletted
30 basn3p02.png 2-bit paletted
31 basn3p04.png 4-bit paletted
32 basn3p08.png 8-bit paletted
33 basn4a08.png 8-bit gray with alpha
34 basn4a16.png 16-bit gray with alpha
35 basn6a08.png 8-bit RGBA
36 basn6a16.png 16-bit RGBA
37
38Here is the correct result of typing "pngtest -m *.png" in
39this directory:
40
41Testing basn0g01.png: PASS (524 zero samples)
42 Filter 0 was used 32 times
43Testing basn0g02.png: PASS (448 zero samples)
44 Filter 0 was used 32 times
45Testing basn0g04.png: PASS (520 zero samples)
46 Filter 0 was used 32 times
47Testing basn0g08.png: PASS (3 zero samples)
48 Filter 1 was used 9 times
49 Filter 4 was used 23 times
50Testing basn0g16.png: PASS (1 zero samples)
51 Filter 1 was used 1 times
52 Filter 2 was used 31 times
53Testing basn2c08.png: PASS (6 zero samples)
54 Filter 1 was used 5 times
55 Filter 4 was used 27 times
56Testing basn2c16.png: PASS (592 zero samples)
57 Filter 1 was used 1 times
58 Filter 4 was used 31 times
59Testing basn3p01.png: PASS (512 zero samples)
60 Filter 0 was used 32 times
61Testing basn3p02.png: PASS (448 zero samples)
62 Filter 0 was used 32 times
63Testing basn3p04.png: PASS (544 zero samples)
64 Filter 0 was used 32 times
65Testing basn3p08.png: PASS (4 zero samples)
66 Filter 0 was used 32 times
67Testing basn4a08.png: PASS (32 zero samples)
68 Filter 1 was used 1 times
69 Filter 4 was used 31 times
70Testing basn4a16.png: PASS (64 zero samples)
71 Filter 0 was used 1 times
72 Filter 1 was used 2 times
73 Filter 2 was used 1 times
74 Filter 4 was used 28 times
75Testing basn6a08.png: PASS (160 zero samples)
76 Filter 1 was used 1 times
77 Filter 4 was used 31 times
78Testing basn6a16.png: PASS (1072 zero samples)
79 Filter 1 was used 4 times
80 Filter 4 was used 28 times
81libpng passes test
82
83Willem van Schaik
84<willem@schaik.com>
85October 1999
86
