1 The *.png and README.original files in this directory are copied from 2 libpng.org, specifically contrib/pngsuite/* in libpng-1.2.40.tar.gz. 3 README.original gives the following license for those files: 4 5 Permission to use, copy, and distribute these images for any purpose 6 and without fee is hereby granted. 7 8 9 The files basn0g01-30.png, basn0g02-29.png and basn0g04-31.png are in fact 10 not part of pngsuite but were created from files in pngsuite. Their non-power- 11 of-two sizes makes them useful for testing bit-depths smaller than a byte. 12 13 basn3a08.png was generated from basn6a08.png using the pngnq tool, which 14 converted it to the 8-bit paletted image with alpha values in tRNS chunk. 15 16 The *.sng files in this directory were generated from the *.png files 17 by the sng command-line tool and some hand editing. The files 18 basn0g0{1,2,4}.sng were actually generated by first converting the PNG 19 to a bitdepth of 8 and then running sng on them. basn4a08.sng was generated 20 by from a 16-bit rgba version of basn4a08.png rather than the original 21 gray + alpha. 22
