Result of the Desaturate filter (Filter -> Adjust -> Desaturate) is slightly (around 2%) colored. This seems to occur regardless of the color mode or depth. Reproducible: Always Steps to Reproduce: 1. Open/create a colored image. 2. Apply the Desaturate Filter. Actual Results: The result image is slightly colored. Expected Results: The result image is complete grayscale just as converted via the Image Properties dialog (Image -> Properties...) or the Convert Layer Type dialog (Layer -> Convert Layer Type...) .
Created attachment 84307 [details] Test image created in RGB, 8 bits/channel, sRGB built-in.
Yes, I can confirm the effect. The code is pretty old, dating back to 2005 and nobody has noticed an issue before...
Git commit 0d6d91d7a120e2eef32f522d970d6392888c09af by Boudewijn Rempt. Committed on 28/12/2013 at 20:59. Pushed by rempt into branch 'calligra/2.8'. There are several ways to do desaturation, so create a kis_desature_adjusment color adjustment that allows to specify the type of desaturation. This replaces the old desat color adjusment that used a Lab-based lut which didn't give correct results. M +0 -5 krita/image/filter/kis_filter.cc M +0 -2 krita/image/filter/kis_filter.h M +10 -9 krita/plugins/colorspaces/extensions/CMakeLists.txt M +3 -0 krita/plugins/colorspaces/extensions/extensions_plugin.cc A +176 -0 krita/plugins/colorspaces/extensions/kis_desaturate_adjustment.cpp [License: LGPL (v2)] A +35 -0 krita/plugins/colorspaces/extensions/kis_desaturate_adjustment.h [License: LGPL (v2)] M +3 -1 krita/plugins/filters/colorsfilters/CMakeLists.txt M +9 -37 krita/plugins/filters/colorsfilters/colorsfilters.cpp M +0 -15 krita/plugins/filters/colorsfilters/colorsfilters.h M +0 -6 krita/plugins/filters/colorsfilters/kis_brightness_contrast_filter.cpp M +0 -2 krita/plugins/filters/colorsfilters/kis_brightness_contrast_filter.h A +122 -0 krita/plugins/filters/colorsfilters/kis_desaturate_filter.cpp [License: GPL (v2+)] C +30 -31 krita/plugins/filters/colorsfilters/kis_desaturate_filter.h [from: krita/plugins/filters/colorsfilters/colorsfilters.h - 061% similarity] M +0 -2 krita/plugins/filters/colorsfilters/kis_hsv_adjustment_filter.h A +64 -0 krita/plugins/filters/colorsfilters/wdg_desaturate.ui M +0 -6 krita/plugins/filters/levelfilter/kis_level_filter.cpp M +1 -2 krita/plugins/filters/levelfilter/kis_level_filter.h M +1 -2 krita/ui/kis_filter_manager.cc M +0 -6 libs/pigment/KoColorSpace.h M +1 -4 libs/pigment/colorspaces/KoAlphaColorSpace.h M +0 -75 plugins/colorengines/lcms2/LcmsColorSpace.h http://commits.kde.org/calligra/0d6d91d7a120e2eef32f522d970d6392888c09af
Git commit 21a3de74d3ae5ee6b6f93865aa36edc5bc8d32e7 by Boudewijn Rempt. Committed on 28/12/2013 at 20:59. Pushed by rempt into branch 'master'. There are several ways to do desaturation, so create a kis_desature_adjusment color adjustment that allows to specify the type of desaturation. This replaces the old desat color adjusment that used a Lab-based lut which didn't give correct results. M +0 -5 krita/image/filter/kis_filter.cc M +0 -2 krita/image/filter/kis_filter.h M +10 -9 krita/plugins/colorspaces/extensions/CMakeLists.txt M +3 -0 krita/plugins/colorspaces/extensions/extensions_plugin.cc A +176 -0 krita/plugins/colorspaces/extensions/kis_desaturate_adjustment.cpp [License: LGPL (v2)] A +35 -0 krita/plugins/colorspaces/extensions/kis_desaturate_adjustment.h [License: LGPL (v2)] M +3 -1 krita/plugins/filters/colorsfilters/CMakeLists.txt M +9 -37 krita/plugins/filters/colorsfilters/colorsfilters.cpp M +0 -15 krita/plugins/filters/colorsfilters/colorsfilters.h M +0 -6 krita/plugins/filters/colorsfilters/kis_brightness_contrast_filter.cpp M +0 -2 krita/plugins/filters/colorsfilters/kis_brightness_contrast_filter.h A +122 -0 krita/plugins/filters/colorsfilters/kis_desaturate_filter.cpp [License: GPL (v2+)] C +30 -31 krita/plugins/filters/colorsfilters/kis_desaturate_filter.h [from: krita/plugins/filters/colorsfilters/colorsfilters.h - 061% similarity] M +0 -2 krita/plugins/filters/colorsfilters/kis_hsv_adjustment_filter.h A +64 -0 krita/plugins/filters/colorsfilters/wdg_desaturate.ui M +0 -6 krita/plugins/filters/levelfilter/kis_level_filter.cpp M +1 -2 krita/plugins/filters/levelfilter/kis_level_filter.h M +1 -2 krita/ui/kis_filter_manager.cc M +0 -6 libs/pigment/KoColorSpace.h M +1 -4 libs/pigment/colorspaces/KoAlphaColorSpace.h M +0 -75 plugins/colorengines/lcms2/LcmsColorSpace.h http://commits.kde.org/calligra/21a3de74d3ae5ee6b6f93865aa36edc5bc8d32e7