pngcheck

PNG file format checker

pngcheck verifies the integrity of PNG, JNG and MNG files (by checking the internal 32-bit CRCs or checksums) and optionally dumps almost all of the chunk-level information in the image in human-readable form. For example, it can be used to print the basic stats about an image (dimensions, bit depth, etc.); to list the color and transparency info in its palette; or to extract the embedded text annotations. All PNG and JNG chunks are supported, plus almost all MNG chunks (everything but PAST, DISC, tERm, DROP, DBYK, and ORDR). This is a command-line program with batch capabilities (e.g., ``pngcheck *.png'').