https://bugs.kde.org/show_bug.cgi?id=424551
Bug ID: 424551 Summary: Gamma error in picture scaling Product: krita Version: 4.3.0-beta1 Platform: Other OS: Linux Status: REPORTED Severity: major Priority: NOR Component: Filter Layers Assignee: krita-bugs-n...@kde.org Reporter: lukasfran...@gmail.com Target Milestone: --- Created attachment 130324 --> https://bugs.kde.org/attachment.cgi?id=130324&action=edit Specially crafted image to demonstrate gamma error SUMMARY Resizing images produces a gamma error. This can clearly be demonstrated by resizing a specially crafted image. It affects all images and worsens the image quality by making them "darker". A more in depth explanation and how to fix this problem can be found on the website http://www.ericbrasseur.org/gamma.html?i=1 STEPS TO REPRODUCE 1. Download "gamma_dalai_lama_gray.jpg" from the attachments 2. Open gamma_dalai_lama_gray.jpg with Krita 3. Proportionally resize the image by doing: 3.1 Image -> Resize Picture 3.2 Tick "Constrain Proportions" and Select "%" 3.3 Pick 50% for width and heigth 3.4 You can pick any one of the filters except Nearest Neighbour 3.5 Press OK ALTERNATVE STEPS TO REPRODUCE 1. Step 1 and 2 as above 2. Scroll down the mouse wheel until the zoom factor is 50% OBSERVED RESULT The image comes out grey or grey with some barely visible outlines. EXPECTED RESULT Picture with natural colors. SOFTWARE/OS VERSIONS Archlinux with kernel 5.6.17 KDE Plasma: (available in About System) KDE Plasma Version: plasma-desktop 5.19.3-1 KDE Frameworks Version: plasma-framework 5.72.0-1 Qt Version: qt5-base 5.15.0-4 ADDITIONAL INFORMATION krita 4.3.0-1 amdgpu-core-meta 19.30_934563-1 xf86-video-amdgpu 19.1.0-2 mesa 20.1.3-1 lib32-mesa 20.1.3-1 libva 2.8.0-1 libva-mesa-driver 20.1.3-1 lib32-libva-mesa-driver 20.1.3-1 mesa-vdpau 20.1.3-1 lib32-mesa-vdpau 20.1.3-1 -- You are receiving this mail because: You are watching all bug changes.