Bug 197218 - MetaDataEdit corrupts CRC information in PNGs
Summary: MetaDataEdit corrupts CRC information in PNGs
Status: RESOLVED FIXED
Alias: None
Product: digikam
Classification: Applications
Component: Plugin-Generic-MetadataEdit (show other bugs)
Version: unspecified
Platform: Debian testing Linux
: NOR normal
Target Milestone: ---
Assignee: Digikam Developers
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2009-06-20 02:41 UTC by Michael G. Hansen
Modified: 2018-03-23 11:32 UTC (History)
0 users

See Also:
Latest Commit:
Version Fixed In: 0.4.0

Attachments
Test-png file without errors, created with inkscape (18.17 KB, image/png)
2009-06-20 03:44 UTC, Michael G. Hansen 		Details
test-1-okay.png modified using MetaDataEdit->Edit Exif, CRC errors (21.19 KB, image/png)
2009-06-20 03:46 UTC, Michael G. Hansen 		Details
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Description Michael G. Hansen 2009-06-20 02:41:46 UTC 
Version:           0.3 (using KDE 4.2.4)
OS:                Linux
Installed from:    Debian testing/unstable Packages

Performing any of the operations that the MetaDataEdit-plugin provides on PNG images leads to corruption of the CRCs in the PNG, as shown by the following libpng warning messages:
libpng warning: zTXt: CRC error
libpng warning: iTXt: CRC error

These are printed to the console by most programs (gimp, kuickshow of kde3, digikam) that open these modified PNGs. All image-data seems to be intact, however (verified using compare of ImageMagick). I only stumbled upon the problem because "pngcrush" aborts on any libpng warnings.
Comment 1 Michael G. Hansen 2009-06-20 03:44:48 UTC 
Created attachment 34665 [details]
Test-png file without errors, created with inkscape
Comment 2 Michael G. Hansen 2009-06-20 03:46:33 UTC 
Created attachment 34666 [details]
test-1-okay.png modified using MetaDataEdit->Edit Exif, CRC errors

test-1-okay.png modified using MetaDataEdit->Edit Exif, set Name to Test.
This file shows CRC errors when opened in kuickshow:

libpng warning: zTXt: CRC error
libpng warning: zTXt: CRC error
libpng warning: iTXt: CRC error
Comment 3 caulier.gilles 2009-06-20 08:17:20 UTC 
This is not the plugin, but Exiv2 library. this problem is fixed with current Exiv2 code from svn (next 0.18.2).

Gilles Caulier