Pngcrush is an optimizer for PNG (Portable Network Graphics) files. It can be
run from a commandline in an MSDOS window, or from a UNIX, LINUX or Amiga
commandline. 

Its main purpose is to reduce the size of the PNG IDAT datastream by trying
various compression levels and PNG filter methods. It also can be used to
remove unwanted ancillary chunks, or to add certain chunks including gAMA,
tRNS, iCCP, and textual chunks.

PERMISSION  UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP     NAME
---------- ----------- ------- ------- ------ ---------- ------------ ----------
[unknown]                 1516    3081  49.2% -lh5- 7a3d Jan 23  2012 pngcrush-m68k/pngcrush.txt
[unknown]               148851  290124  51.3% -lh5- eaab Sep 30 13:13 pngcrush-m68k/pngcrush
[unknown]                 1506    3207  47.0% -lh5- f667 Mar 31  2016 pngcrush-m68k/LICENSE
[unknown]                17331   47920  36.2% -lh5- 9587 Aug 29 21:15 pngcrush-m68k/ChangeLog.html
---------- ----------- ------- ------- ------ ---------- ------------ ----------
 Total         4 files  169204  344332  49.1%            Sep 30 19:15