pngcheck(1) Test PNG image files for corruption, display size, type, compression info


pngcheck [-vqt7f] file.png [file.png [...]]
pngcheck [-vqt7f] file.mng [file.mng [...]]
pngcheck -{sx}[vqt7f] file-containing-PNGs...
Can be used in pipe:
... | pngcheck [-sx][vqt7f]


Print contents of text chunks, escape chars >=128 (for 7-bit terminals).
Force continuation even after major errors.
Display contents of PLTE, tRNS, hIST, sPLT and PPLT (can be used with -q).
Test quietly (only output errors).
Search for PNGs within another file.
Display contents of tEXt chunks (can be used with -q).
test verbosely (print most chunk data).
Search for PNGs and extract them when found.


pngcheck is the official PNG tester and debugger. Originally designed simply to test the CRCs within a PNG image file (e.g., to check for ASCII rather than binary transfer), it has been extended to check and optionally print almost all the information about a PNG image and to verify that it conforms to the PNG specification. It also includes partial support for MNG animations.

It can dump 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).






Program was written by Greg Roelofs <[email protected]>, <[email protected]>.

This manual page was written by Kevin M. Rosenberg <[email protected]> for the Debian GNU system (but may be used by others). Updated and converted to Perl POD source format by Jari Aalto <[email protected]>. Released under license GNU GPL v2 or (at your option) any later version. For more information about license, visit <>.