https://bugs.kde.org/show_bug.cgi?id=451629
Bug ID: 451629 Summary: Greyscale Layers have incorrect peak white display. Product: krita Version: nightly build (please specify the git hash!) Platform: Debian stable OS: Linux Status: REPORTED Severity: normal Priority: NOR Component: Color models Assignee: krita-bugs-n...@kde.org Reporter: ahab.greybe...@hotmail.co.uk Target Milestone: --- SUMMARY This problem is not in the 5.0.2 or previous versions. It has been introduced in the 5.1.0-prealpha and the 5.0.2-alpha (Stable/Plus) and is being reported for the Mar 16 5.1.0-prealpha (git df3e78e899) appimage on Debian 10. If a Greyscale/Alpha layer is created by any means and maximum white is painted on the layer, the colour shown is a mid-dark grey colour of about 30% in appearance. However, the Colour Sampler Tool says this is Grey 255, Alpha 255 The Specific Colour Selector shows it as RGB = 80, 80, 80. All shades of grey that are less than peak white are correctly presented. Using the Specific Colour Selector to choose an RGB colour, for painting on a Greyscale layer, shows the following behaviour: RGB = 255, 255, 255 gives the 30% grey colour that corresponds to RGB = 80, 80, 80 If Green is reduced to 254 (with Red, Blue = 255, 255) then the correct shade of white is painted. If Red or Blue are reduced to 254 (with Green = 255), fake grey is painted. If Green is kept at 255 and Red, Blue are set to 253, 253, then the correct shade of white is painted. If the peak white 'fake grey' is painted over a different shade of grey then a white outline appears at the edge of the stroke even if anti-aliasing of the brush is turned off. This is not affected by the Canvas Graphics Acceleration or the Scaling Mode. Converting the layer to RGB/A 8-bit results in the peak white 'fake grey' remaining grey but slightly lighter as RGB = 85,85,85. The same thing is seen if a Transparency Mask with peak white on it is converted to a Paint Layer or if an RGB layer with peak white on it is converted to Greyscale/Alpha. Similar behaviour is shown for 16-bit integer colour spaces but the fake grey is a slightly lighter shade. STEPS TO REPRODUCE See Summary OBSERVED RESULT See Summary EXPECTED RESULT Peak white should display as peak white and be preserved as that during Colour Space conversion. SOFTWARE/OS VERSIONS Krita Version: 5.1.0-prealpha (git df3e78e) Languages: en_GB, en, en, en_GB, en Hidpi: false Qt Version (compiled): 5.12.12 Version (loaded): 5.12.12 OS Information Build ABI: x86_64-little_endian-lp64 Build CPU: x86_64 CPU: x86_64 Kernel Type: linux Kernel Version: 4.19.0-18-amd64 Pretty Productname: Debian GNU/Linux 10 (buster) Product Type: debian Product Version: 10 Desktop: MATE OpenGL Info Vendor: "NVIDIA Corporation" Renderer: "GeForce GTX 750 Ti/PCIe/SSE2" Version: "4.6.0 NVIDIA 460.73.01" Shading language: "4.60 NVIDIA" Requested format: QSurfaceFormat(version 3.0, options QFlags<QSurfaceFormat::FormatOption>(DeprecatedFunctions), depthBufferSize 24, redBufferSize 8, greenBufferSize 8, blueBufferSize 8, alphaBufferSize 8, stencilBufferSize 8, samples -1, swapBehavior QSurfaceFormat::DoubleBuffer, swapInterval 0, colorSpace QSurfaceFormat::DefaultColorSpace, profile QSurfaceFormat::CompatibilityProfile) Current format: QSurfaceFormat(version 4.6, options QFlags<QSurfaceFormat::FormatOption>(DeprecatedFunctions), depthBufferSize 24, redBufferSize 8, greenBufferSize 8, blueBufferSize 8, alphaBufferSize 8, stencilBufferSize 8, samples -1, swapBehavior QSurfaceFormat::DoubleBuffer, swapInterval 0, colorSpace QSurfaceFormat::DefaultColorSpace, profile QSurfaceFormat::CompatibilityProfile) Version: 4.6 Supports deprecated functions true is OpenGL ES: false supportsBufferMapping: true supportsBufferInvalidation: true ADDITIONAL INFORMATION -- You are receiving this mail because: You are watching all bug changes.