pngcheck verifies the integrity of PNG, JNG and MNG files (by checking the internal 32-bit CRCs {} and decompressing the image {data);} it can optionally dump almost all of the chunk-level information in the image in human-readable form. For example, it can be used to print the basic statistics about an image (dimensions, bit depth, {etc.);} to list the color and transparency info in its palette (assuming it has {one);} or to extract the embedded text annotations. This is a command-line program with batch capabilities.

WWW: https://www.libpng.org/pub/png/apps/pngcheck.html
