pngcheck |
pngcheck verifies the integrity of PNG, JNG and MNG files (by checking the internal 32-bit CRCs [checksums] 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.
Here's some sample output (screen shots, eh?):
% pngcheck -vt ArcTriomphe-iCCP-red-blue-swap.png File: ArcTriomphe-iCCP-red-blue-swap.png (5171 bytes) chunk IHDR at offset 0x0000c, length 13 64 x 64 image, 8-bit colormap, non-interlaced chunk iCCP at offset 0x00025, length 461 profile name = Swapped red & blue channel compression method = 0 (deflate), compressed profile = 433 bytes chunk PLTE at offset 0x001fe, length 759: 253 palette entries chunk IDAT at offset 0x00501, length 3616 zlib: deflated, 32K window, default compression chunk tEXt at offset 0x0132d, length 68, keyword: Title PNG color-correction test image, swapped red and blue channels chunk tEXt at offset 0x0137d, length 143, keyword: Copyright Copyright 2005 Greg Roelofs. Licensed under Creative Commons AttributionNonCommercial, http://creativecommons.org/licenses/by-nc/2.5/ chunk tIME at offset 0x01418, length 7: 16 Aug 2005 07:07:07 GMT chunk IEND at offset 0x0142b, length 0 No errors detected in ArcTriomphe-iCCP-red-blue-swap.png (8 chunks, -26.2% compression). % pngcheck *.png OK: 000000.png (48x48, 1-bit grayscale, non-interlaced, 71.2%). OK: 000033.png (48x48, 1-bit colormap, non-interlaced, 66.0%). OK: 000066.png (48x48, 1-bit colormap, non-interlaced, 66.0%). OK: 000099.png (48x48, 1-bit colormap, non-interlaced, 66.0%). [...] OK: ffff66.png (48x48, 1-bit colormap, non-interlaced, 66.0%). OK: ffff99.png (48x48, 1-bit colormap, non-interlaced, 66.0%). OK: ffffcc.png (48x48, 1-bit colormap, non-interlaced, 66.0%). OK: ffffff.png (48x48, 1-bit grayscale, non-interlaced, 70.1%). No errors were detected in the 216 files tested.
The current release supports all PNG, MNG and JNG chunks, including the newly approved sTER stereo-layout chunk. It correctly reports errors in all but two of the images in Chris Nokleberg's brokensuite-20061204. Also included (since version 2.1.0) are two helper utilities:
The new utilities are licensed under the GNU General Public License (GPL); pngcheck itself remains under its original, MIT/X11-style license.
Current version: | 2.3.0 | ||||||
Authors: | Alexander Lehmann, Andreas Dilger, Greg Roelofs | ||||||
License: | Open Source | ||||||
Platforms: | Unix, DOS, OS/2, Windows, Macintosh, Amiga, etc. | ||||||
README: |
local web site http://www.libpng.org/pub/png/src/ ftp://ftp.simplesystems.org/pub/libpng/png/applications/ |
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ChangeLog: |
local web site http://www.libpng.org/pub/png/src/ ftp://ftp.simplesystems.org/pub/libpng/png/applications/ |
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Binaries: |
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Source code: |
http://prdownloads.sourceforge.net/ (.tar.gz) http://prdownloads.sourceforge.net/ (.zip) ftp://ftp.simplesystems.org/pub/libpng/png/applications/ (.tar.gz) ftp://ftp.simplesystems.org/pub/libpng/png/applications/ (.zip) |
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Supporting libraries: |
zlib |
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Related software: | pngmeta - PNG meta-information extractor |
Copyright © 2000-2007 Greg Roelofs.