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PNGCHUNKS(1) PNGCHUNKS(1)

NAME

pngchunks - print information embedded into a PNG file

SYNOPSIS



 pngchunks

DESCRIPTION

pngchunks is a program that displays informations from files created according to the Portable Network Graphics file format.

EXAMPLE



       pngchunks input.png Chunk: Data Length 13 (max 2147483647), Type 1380206665 [IHDR]


         Critical, public, PNG 1.2 compliant, unsafe to copy


         IHDR Width: 256


         IHDR Height: 256


         IHDR Bitdepth: 8


         IHDR Colortype: 2


         IHDR Compression: 0


         IHDR Filter: 0


         IHDR Interlace: 0


         IHDR Compression algorithm is Deflate


         IHDR Filter method is type zero (None, Sub, Up, Average, Paeth)


         IHDR Interlacing is disabled


         Chunk CRC: -753909967 Chunk: Data Length 6 (max 2147483647), Type 1145523042 [bKGD]


         Ancillary, public, PNG 1.2 compliant, unsafe to copy


         ... Unknown chunk type


         Chunk CRC: 554438993 Chunk: Data Length 9 (max 2147483647), Type 1935231088 [pHYs]


         Ancillary, public, PNG 1.2 compliant, safe to copy


         ... Unknown chunk type


         Chunk CRC: -757235972 Chunk: Data Length 7 (max 2147483647), Type 1162692980 [tIME]


         Ancillary, public, PNG 1.2 compliant, unsafe to copy


         ... Unknown chunk type


         Chunk CRC: 429243611 Chunk: Data Length 831 (max 2147483647), Type 1413563465 [IDAT]


         Critical, public, PNG 1.2 compliant, unsafe to copy


         IDAT contains image data


         Chunk CRC: 1406256926 Chunk: Data Length 0 (max 2147483647), Type 1145980233 [IEND]


         Critical, public, PNG 1.2 compliant, unsafe to copy


         IEND contains no data


         Chunk CRC: -1371381630

SEE ALSO

pngchunkdesc(1), pngcp(1), pnginfo(1).

VERSION

This documentation is for pngtools 1.0.

AUTHOR

pngtools was written by Michael Still and is released under the GNU GPL. The project is hosted at https://github.com/mikalstill/pngtools.

BUGS

Please report bugs at https://github.com/mikalstill/pngtools/issues.

25 February 2026 User Commands