Last modified: 2012-09-20 17:36:57 UTC
From a question on the nl-wiki helpdesk: https://nl.wikipedia.org/w/index.php?title=Help:Helpdesk&oldid=30537151#Afbeelding_bij_P.J._Proby The mentioned picture itself looks ok: https://commons.wikimedia.org/wiki/File:P.J._Proby_2007.jpg But if you take the 263px version (size for inside a dutch infobox, the image seems to be rendered completely wrong (darker): https://upload.wikimedia.org/wikipedia/commons/thumb/3/3b/P.J._Proby_2007.jpg/263px-P.J._Proby_2007.jpg Did something go wrong with image scaling?
This problem comes up periodically, so I've posted a query here: http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=20898
Mark: seen that they ask 'More information on exact you are operating on the images is needed.'?
Summary of the forum discussion: the image has a CMYK colourspace. ImageMagick does not convert the image to RGB, instead its many operators are expected to deal with CMYK buffers correctly. Some work, some fail spectacularly, even reading from arbitrary memory. I've confirmed that the source image and the generated thumbnails are CMYK. Probably adding "-colorspace rgb" to the ImageMagick command line would fix it.
I've uploaded an RGB version to Commons, to fix the articles using this image. The original test case is now at <https://upload.wikimedia.org/wikipedia/commons/archive/3/3b/20120507074031!P.J._Proby_2007.jpg> Reducing priority since I assume this problem is very rare, given the low rate of reports.
(In reply to comment #4) > Reducing priority since I assume this problem is very rare, given the low rate > of reports. It is. Thanks for your help.
(In reply to comment #4) > The original test case is now at > > <https://upload.wikimedia.org/wikipedia/commons/archive/3/3b/20120507074031!P.J._Proby_2007.jpg> Are you sure that is the original? I can't reproduce the original problem on my lucid box.
Yes, that is the correct source image, and the history thumbnail still shows the problem: <https://upload.wikimedia.org/wikipedia/commons/thumb/archive/3/3b/20120507074031!P.J._Proby_2007.jpg/96px-P.J._Proby_2007.jpg>
(In reply to comment #1) > This problem comes up periodically, so I've posted a query here: > http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=20898 Thank you for your query. I think this bug is a duplicate of bug 24854. Could so. please resolve duplicate this one?
(In reply to comment #8) It seems I don't have the rights to mark this as dupl. Could so else please do this?
(In reply to comment #9) > (In reply to comment #8) > It seems I don't have the rights to mark this as dupl. Could so else please do > this? Done. *** This bug has been marked as a duplicate of bug 24854 ***
