Release Notes: Version 1.7.18 failed to read interlaced PNGs. This problem is fixed in this release.
Release Notes: This release fixes a bug with the new "-reduce" option which would remove the alpha channel even when it was not all-opaque.
Release Notes: This release fixes a bug introduced in 1.7.52 which caused the -reduce option to produce a tRNS chunk which had more entries than the PLTE chunk (which is invalid).
Release Notes: This release fixes initialization problems introduced in version 1.7.51, reinitializes settings before processing each file, and makes the "-reduce" option work properly.
Release Notes: This version implements the "-reduce" option properly. This examines the input file to see if the color type, bit depth, and palette length can be reduced without loss, and if there is an opaque alpha channel which can be removed.
Release Notes: This release fixes a bug introduced in version 1.7.39 which caused failure to write an output file.