| Summary: | Automatic text color for table cell bg of RGB=(0,255,0) is White, should be Black | ||
|---|---|---|---|
| Product: | LibreOffice | Reporter: | Eyal Rozenberg <eyalroz1> |
| Component: | LibreOffice | Assignee: | Not Assigned <libreoffice-bugs> |
| Status: | RESOLVED DUPLICATE | ||
| Severity: | normal | CC: | heiko.tietze, suokunlong, vsfoote |
| Priority: | medium | Keywords: | bisected, regression |
| Version: | 24.8.0.0 alpha0+ | ||
| Hardware: | All | ||
| OS: | All | ||
| URL: | https://ask.libreoffice.org/t/when-i-change-the-cell-background-colour-the-text-colour-changes-how-can-i-stop-this/106368 | ||
| Whiteboard: | |||
| Crash report or crash signature: | Regression By: | ||
| Bug Depends on: | |||
| Bug Blocks: | 142074 | ||
Confirm. In Writer, but also copied the table from Writer to Calc. Where for see also bug 156182 at 24.2.0 the luminance/contrast threshold was adjusted. Yet in Calc the Automatic formatting for text on a 0,255,0 bg cell remains white. So are we just not testing the luminance contrast threshold in appropriate fashion? Or do the IsDark() / IsLight() GetLuminance() ranges for RGB greens somehow in need a different test? @Heiko? Version: 24.8.0.0.alpha0+ (X86_64) / LibreOffice Community Build ID: 30c6e51fc9cb0fa864e1755271343d847fcced25 CPU threads: 8; OS: Windows 10.0 Build 19045; UI render: Skia/Raster; VCL: win Locale: en-US (en_US); UI: en-US Calc: CL threaded (In reply to V Stuart Foote from comment #1) Thanks. Indeed, the behavior is the same in Calc, and I had forgotten to mention I was using: Version: 24.2.0.2 (X86_64) / LibreOffice Community Build ID: b1fd3a6f0759c6f806568e15c957f97194bbec8f CPU threads: 4; OS: Linux 6.6; UI render: default; VCL: gtk3 Locale: en-IL (en_IL); UI: en-US I should also say, that the "problem" is not with the Brightness value I mentioned earlier; for Red, i.e. RGB = (255,0,0), the use of White text is fine, and probably even a little better than Black. It's also not about Luminance/Lightness, in the HSL model, since for both Red and Green, the L value is 50%. Obviously an issue with the luminance calculation and/or the used threshold for dark. I suggest to discuss this topic on bug 156182. So, this is a regression after commit ddb483509113e469b771320fea52f1b089574021 (Resolves tdf#156182 - Automatic text color unreadable with darker cells, 2023-07-15). Adding respective keywords. Any such change, even with a different threshold, will necessary break some existing documents. Maybe that is worth a special compat flag, but at least this fact should be considered. *** Bug 159983 has been marked as a duplicate of this bug. *** *** This bug has been marked as a duplicate of bug 158989 *** |
Consider this document: attachment 112798 [details] (it discusses another bug, but that's not important). In that document, we have a table. All table cells' text color is Automatic. Some of these table cells have background color RGB = (0,255,0), i.e. full Green with no Red or Blue. LibreOffice choose White for the text color in this case. However - White is a poor choice here: Ihas a lot less contrast, with this kind of Green (which, btw, has a brightness value of 100%); Black would have been a much better choice. Not sure what the color choice logic is, but its result in this case is off.