1699
1699
As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
1700
1700
added. It expands the sample depth without changing tRNS to alpha.
1704
1704
In the following table, the 01 means grayscale with depth<8, 31 means
1705
1705
indexed with depth<8, other numerals represent the color type, "T" means