Forensics tool for validating the integrity of PNG based (PNG, JNG, MNG) image files. Can also extract embedded images and text from a file. More information: http://www.libpng.org/pub/png/apps/pngcheck.html.
pngcheck path/to/file.png
pngcheck -vc path/to/file.png
pngcheck -ts path/to/file.png
pngcheck -x path/to/file.png