When showing thumbnails of PNG with alpha channel to mask areas of picture, digikam ignore it. Reproducible: Always Steps to Reproduce: 1.Create a PNG with alpha channel and save with it 2.Show that PNG thumbnail on digikam Actual Results: Whole PNG picture is showed. Expected Results: Do not show alpha areas from image on thumbnails, like Gwenview does. User can't distinguish between PNG images with and w/o alpha channel, so he need to preview it.
Which version of digiKam do you use ? Can you share some PNG images with Alpha ? Gilles Caulier
Sorry for the delay. digikam 4.11.0
Created attachment 93810 [details] Our friend
Created attachment 93811 [details] Colour dices
Created attachment 93812 [details] A good example with levels of opacity
Created attachment 93823 [details] alphathumbs.png DigiKam used as well as Dolphin a white background. Gwenview uses the background color. I think it is not difficult to change this, but somehow I find the white background better. What do you think Gilles? Maik
yes the code relevant is in icon-view model-view. Internally, we use PGF to store thumbs. PGF support Alpha, so, it's not a problem in this side. Look in core/libs/threadimageio/pgfutils.cpp to be sure. There are code PGF <->QImage conversion. DB store PGF as RAW data. In core/tests, there is also a CLI tool to check PGF conversion with image samples. Gilles
Hi Maik From a photographer/designer viewpoint, we need to distinguish at a glance alpha masked images from not alpha masked (cause digikam can't distinguish one from each other in a search).
Created attachment 93881 [details] checkerboard.png Hi Rafael Depending on the color scheme, we have different background colors. What do you think over the checkerboard in the background, as in the screenshot? Maik
I think is a perfect way to show the thumbs, cause you can see if the object is or is not centered. ;)
Created attachment 93918 [details] checkerboard2.png I once made a brighter checkerboard. What is better? Maik
Created attachment 93919 [details] checkerboard.patch Here is the patch for the checkerboard. Maik
I think that bright is perfect. Thank you. Finally I will not need to open each PNG file to see how it will be showed. ;)
Git commit b6ef05138531969b771bff59e750aa82340dd268 by Maik Qualmann. Committed on 08/08/2015 at 16:50. Pushed by mqualmann into branch 'master'. has the thumbnail a alpha channel, is a checkerboard background used FIXED-IN: 4.13.0 M +2 -1 NEWS M +10 -1 libs/threadimageio/thumbnailcreator.cpp http://commits.kde.org/digikam/b6ef05138531969b771bff59e750aa82340dd268
Git commit 80f5fa781ddcf3e9033f0ef405d0834a0b74ffe0 by Maik Qualmann. Committed on 11/08/2015 at 06:03. Pushed by mqualmann into branch 'frameworks'. backport commit #b6ef05138531969b771bff59e750aa82340dd268 from git/master to frameworks branch M +10 -1 libs/threadimageio/thumbnailcreator.cpp http://commits.kde.org/digikam/80f5fa781ddcf3e9033f0ef405d0834a0b74ffe0