Text file src/image/png/testdata/pngsuite/README

Documentation: image/png/testdata/pngsuite

     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.

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