Bug report #8524
Raster tiling offset in composer output from zoomed in resampling
|Affected QGIS version:||master||Regression?:||No|
|Operating System:||OS X||Easy fix?:||No|
|Pull Request or Patch supplied:||No||Resolution:||end of life|
|Crashes QGIS or corrupts data:||No||Copied to github as #:||17280|
The composer is creating raster artifacts that appear to be from some form of tiling in both pdf and png outputs. See the attached sample image that shows the non-alignment in raster layer output. It appears to be a shift in the raster "tiles".
#1 Updated by John Tull over 6 years ago
I repeated printing without the affected layer (sans heat map tif layer), and the tiling offset does not occur. I cannot think of anything unique about this layer that would make it do this, except perhaps image resampling. Indeed, switching the "zoomed in" resampling from "bilinear" to "nearest neighbour" produced an output without the tiling offset. Unfortunately, the image quality is not what I was hoping for. I tried "cubic", and it also suffers from the tiling offset problem.
In short, it appears that the zoomed in resampling for either bilinear or cubic is causing problems in the composer. This problem is not visible in the map canvas or in the composer preview, only in the output.
#8 Updated by Oliver Story almost 4 years ago
- Status changed from Closed to Reopened
- File Raster_artifact_test.qgs added
- File Raster_artifact_demo.png added
This is still an issue for me in QGIS 2.12.3
I've uploaded a test project and a screenshot; raster available from https://www.dropbox.com/s/li7uxhribg89b3m/hillshade.zip?dl=0 as it's 7MB and I couldn't upload it.
For me the issue occurs with bilinear or cubic resampling, in print composer window and when exported as image or PDF (probably when exported as SVG too but I haven't tried this).
#10 Updated by Giovanni Manghi 11 months ago
- Status changed from Reopened to Closed
- Resolution changed from worksforme to end of life
End of life notice: QGIS 2.18 LTR