Print detailed information about and verify PNG, JNG, and MNG files. More information: http://www.libpng.org/pub/png/apps/pngcheck.html.
pngcheck image.png
pngcheck -c image.png
pngcheck -cvt image.png
stdin
and display detailed information:cat path/to/image.png | pngcheck -cvt
pngcheck -s image.png
pngcheck -x image.png