Opened 9 years ago
Closed 5 years ago
#5767 closed defect (wontfix)
gdal_calc: input data type used for output values
Reported by: | cdestigter | Owned by: | Robert Coup |
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Priority: | normal | Milestone: | closed_because_of_github_migration |
Component: | PythonBindings | Version: | svn-trunk |
Severity: | normal | Keywords: | |
Cc: | antonio |
Description (last modified by )
We're using gdal_calc.py like this to replace alpha with nodata (-1) in RGBA and grey+alpha images:
gdal_calc.py -A in.tif -B in.tif --A_band 2 --B_band 1 --outfile out.tif --calc="where(A < 128, -1, B)" --type=Int16 --NoDataValue=-1
The --calc formula should replace all transparent-ish pixels with -1, which is a valid value for the output image because it's an Int16 image.
However it seems gdal_calc is doing the type conversion implicitly, after the output values are calculated. So the -1 gets wrapped into a byte, and the values all get set to 255 instead of -1.
This patch fixes the problem by explicitly converting the array's data type, earlier in the process: https://github.com/koordinates/gdal/commit/efea5dafaf536213faadbbc3f671591aa6aa8c30
Change History (3)
comment:1 by , 9 years ago
Description: | modified (diff) |
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Owner: | changed from | to
comment:2 by , 9 years ago
Cc: | added |
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comment:3 by , 5 years ago
Milestone: | → closed_because_of_github_migration |
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Resolution: | → wontfix |
Status: | new → closed |
This ticket has been automatically closed because Trac is no longer used for GDAL bug tracking, since the project has migrated to GitHub. If you believe this ticket is still valid, you may file it to https://github.com/OSGeo/gdal/issues if it is not already reported there.