Last modified: 2014-05-23 01:29:51 UTC
Created attachment 8669 [details] miscoloured thumbnail I just found an image on Wikipedia whose thumbnail has all of black turned into white. Even more interesting, this is not restricted to pure black as antialiased edges are white as well. Strangely, other colours are nearly unaltered -- dark ones are slightly brightened while bright ones slightly darker but the change is minimal. The image is https://secure.wikimedia.org/wikipedia/en/wiki/File:Vietnam_POW_Camps.jpg, thumbnail size: 885×768.
Weird... I can confirm doing some current resizing on it. Only unusual thing I notice about the source file is it's listed as 32bit rather than the usual 24bit; not sure what exactly that means in this context since jpeg doesn't do alpha.
If you change it to a 24bit image and then do the thumbnailing, does the anti-aliasing change? Seems like an ImageMagick bug, really
Looks like an icc profile - U.S. Web Coated (SWOP) v2 (black without it, white with the profile) Now a days, thumbnails keep their colour profiles, so I'm going to call this worksforme, as display is consistent (although may vary between browsers).
