Background: digikam 5.4.0-2 from Arch Linux packages. My colour-management settings: enabled working = BestRGB Monitor profile = specified an ICC file generated from displayCal Use colour-managed view in editor: enabled Use colour-managed view for previews and thumbnails: enabled Advanced: Use black-point; perceptual Problem: I am working with the image http://misc.sty.nu/IMGP0431_1-large_v1.tiff (21MB) which uses the ProPhotoRGB-linear profile. In the preview it looks utterly ghastly, with massively quantized shadow areas. See http://misc.sty.nu/digikam-screenshot-preview.png However, in the editor it looks fine: http://misc.sty.nu/digikam-screenshot-editor.png (I used the "keep" option on opening, so there remains a ProPhotoRGB->monitor-space transformation in place to display this.) This inaccuracy in the preview makes it difficult to compare/rate images that rely on shadow zones in ProPhotoRGB-linear space. I have tried varying the colour-management Advanced settings and no combination of blackpoint compensation nor rendering intent makes it go away - and some look even worse. The problem does go away when I convert the image to sRGB, but changing now would be premature in the workflow - there are lots of blends and edits pending in multiple utilities yet. I would understand if it was my monitor calibration profile being low quality, but how come the editor can get it right, so why can't the preview show the same thing?
Your image has 14 bits. The preview load for speed reasons images only in 8 bits. The Image Editor can load 16 bits images. Maik
Git commit 0ca4c66af71b2364d69d28cdff4e5364e42db28a by Maik Qualmann. Committed on 24/02/2017 at 20:29. Pushed by mqualmann into branch 'master'. make it possible to disable converting preview image to 8 bits FIXED-IN: 5.5.0 M +2 -1 NEWS M +2 -0 libs/settings/applicationsettings.cpp M +1 -0 libs/settings/applicationsettings_p.cpp M +1 -0 libs/settings/applicationsettings_p.h M +6 -4 libs/threadimageio/previewsettings.cpp M +2 -2 libs/threadimageio/previewsettings.h M +4 -1 libs/threadimageio/previewtask.cpp M +20 -12 utilities/setup/album/setupalbumview.cpp https://commits.kde.org/digikam/0ca4c66af71b2364d69d28cdff4e5364e42db28a
Many thanks!