Bug report #7756
transparent pixel list values not applied to RGB raster if contrast enhancement inactive
| Status: | Closed | ||
|---|---|---|---|
| Priority: | Severe/Regression | ||
| Assignee: | - | ||
| Category: | Rasters | ||
| Affected QGIS version: | master | Regression?: | No |
| Operating System: | Easy fix?: | No | |
| Pull Request or Patch supplied: | No | Resolution: | duplicate |
| Crashes QGIS or corrupts data: | No | Copied to github as #: | 16656 |
Description
User-added transparent pixel values are ignored when contrast enhancement is set to "no enhancement" with RGB rasters. I'm seeing this issue with LANDSAT-7 tiles
Steps to reproduce:
1. Open a new project, make sure the map canvas background color is white
2. Load a RGB-based raster (LANDSAT-7 3-band composite is perfect)
3. Open the raster's layer properties window
4. Make sure that the contrast enhancement is set to "no enhancement" in the Style tab
5. Go to the Transparency tab, and add a transparent value manually via button (set the transparency value to Red=0,Green=0,Blue=0,Percent Transparent=100
6. Apply the settings
At this stage, the raster should redraw with any black (RGB=0,0,0) value being transparent and see through. However, QGIS now fails to make the black values transparent. If you go back into the raster layer properties's Style tab and enable contrast enhancement - say "Stretch to MinMax", the user-set transparent values will be taken into account.
History
#1
Updated by Mathieu Pellerin - nIRV over 11 years ago
Note: I'm not seeing this regression on a single band raster.
#2
Updated by Mathieu Pellerin - nIRV over 11 years ago
I've actually uploaded a LANDSAT-7 3-band true color geotiff to facilitate the testing. It's available here: http://licadho-cambodia.org/raster/321.zip (64mb)
#3
Updated by Giovanni Manghi over 11 years ago
- Resolution set to duplicate
- Status changed from Open to Closed
duplicate of #7748