optipng

PNG file optimization utility. More information: http://optipng.sourceforge.net.

• Compress a PNG with default settings:
  optipng {{path/to/file.png}}
• Compress a PNG with the best compression:
  optipng -o{{7}} {{path/to/file.png}}
• Compress a PNG with the fastest compression:
  optipng -o{{0}} {{path/to/file.png}}
• Compress a PNG and add interlacing:
  optipng -i {{1}} {{path/to/file.png}}
• Compress a PNG and preserve all metadata (including file timestamps):
  optipng -preserve {{path/to/file.png}}
• Compress a PNG and remove all metadata:
  optipng -strip all {{path/to/file.png}}