Opened 15 years ago
Closed 15 years ago
#2735 closed defect (fixed)
Cutline with blend gives wrong results inside cut polygon
Reported by: | asgerpetersen | Owned by: | warmerdam |
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Priority: | normal | Milestone: | 1.6.1 |
Component: | Algorithms | Version: | 1.6.0 |
Severity: | normal | Keywords: | blend forceToMultiLineString |
Cc: |
Description
Outside the cut polygon the rasters are correctly blended together over the specified blending distance. Inside the cut polygon the rasters are blended 50/50 all over.
Please find a simple example attached. In the example a white (one band, all values = 255) and a black (one band, all values = 0) are cut together using blending. Outside the polygon everything looks perfect. Inside the polygon all pixels are gray (value = 128).
Attachments (1)
Change History (2)
by , 15 years ago
comment:1 by , 15 years ago
Keywords: | forceToMultiLineString added |
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Milestone: | → 1.6.1 |
Resolution: | → fixed |
Status: | new → closed |
I have determined that the problem was OGRGeometryFactory::forceToMultiLineString() was not working for MultiPolygons (though it does for Polygons). This resulted in points inside always being at a distance of zero from the cutline and so being treated as 50% intensity.
I have fixed this in trunk (r15944), and 1.6 branch (r15945).
I see forceToMultiLineString() is significantly less useful in 1.5 so no point in backporting this change.
Zip file containing input raster files, shp cut polygon, bat-script and the resulting output