Bug report #17845
Setting Raster Transparency using "Add values from display" doesn't work
|Affected QGIS version:||master||Regression?:||Yes|
|Operating System:||Windows 10 & Ubuntu Linux 16.04 LTS||Easy fix?:||No|
|Pull Request or Patch supplied:||Yes||Resolution:|
|Crashes QGIS or corrupts data:||Yes|
If I try to set the Transparent Pixels using "Add values from display" it gives no result. If I close the Layer Properties window after using "Add values from display" using OK or Cancel, QGIS becomes unresponsive on Windows and closes without a warning on Ubuntu.
Also the Layer Properties window remains minimized after clicking in the map window when trying to use "Add values from display".
#2 Updated by Michel Stuyts 10 days ago
I tested it with multiple raster-files (TIF and PNG). One of those files can be downloaded from: https://downloadagiv.blob.core.windows.net/winterbedkaart/Winterbedkaart+(Watertoets).zip
- Start a new project in QGIS 2.99
- Add the downloaded tiff-file (Wtrbed.tif)
- Open the layer Properties Window
- Go to the "Transparency" tab
- Click on the "add values from display" button (now the Properties Window remains the same size on Ubuntu Linux and minimizes on Windows)
- Click somewhere on the white (or another color) part in the Map Window (now the Properties Window remains minimized on Windows)
- On Windows double click on the minimized topbar of the Properties Window on the bottom left of the screen to maximize it. (now no color values are added to the "Transparent pixel list" on both Windows and Ubuntu Linux)
- Click on the OK or Cancel button
- On an Windows 10 machine: the Properties window closes, but clicking anywhere in the main window has no effect. QGIS can only be closed by using Windows Task Manager and killing the process
- On an Ubuntu Linux machine: QGIS closes without a warning.