Am Donnerstag, 15. Juni 2017, 00:49:09 CEST schrieb Émile Cordonnier: > Hi, > > I have *jpg* files (not post-processed by me) for which I suspect a problem > with icc profile (not because of darktable, but darktable seems to reveal > the problem) : > > > - When I open them in the darkroom, there is less contrast and > saturation than in the original full-screen lighttable thumbnail. > - If in the "input color profile" module I change from "embedded ICC > profile" to "Adobe RGB", the contrast and color are the same as the > initial thumbnail in the lighttable. > - If I modify the image (like change back to "embedded ICC") and go back > to lighttable, the thumbnail is now like in the darkroom (little > contrast/saturation). > > > The embedded ICC profile is sRGB. I suspect that the embedded ICC profile > is wrong and should have been AdobeRGB (this behavior in darktable appears > only for images post-processed by Capture NX-D, not images from camera sent > by the same person).
Could you send me such a file? I'd like to have a look, just to be sure. > What I don't understand, though, is why the first thumbnail in lightable > was different (like with an AdobeRGB profile). > I have read 2.2.3.1. Thumbnail creation > <http://www.darktable.org/usermanual/ch02s02s03.html.php> and color manage > cached thumbnails <http://www.darktable.org/usermanual/ch08s02.html.php> (it > is on), but I still does not understand this case. I use darktable 2.2.5. > > If someone has an explanation... What I guess is happening is this: The JPEGs have an embedded preview which is used by darktable initially. This one seems to be correct wrt. color profiles. The image itself however is most likely using the wrong profile (I can only tell for sure once I got such a file) and thus shows wrong colors. Once the image was opened in darkroom darktable creates its own (wrong) thumbnail and uses that. > Thank you, > Émile Tobias
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