Opened 12 years ago
Closed 8 years ago
#3917 closed enhancement (wontfix)
COPY_SRC_OVERVIEWS option of gdal_translate incompatible with -outsize and -srcwin
Reported by: | jcrepetto | Owned by: | warmerdam |
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Priority: | normal | Milestone: | |
Component: | Utilities | Version: | svn-trunk |
Severity: | normal | Keywords: | |
Cc: |
Description
I have a file containing overviews :
$ gdalinfo -noct World.ozf2 Driver: OZI/OZI Files: World.ozf2 Size is 2108, 2048 Coordinate System is `' Band 1 Block=64x64 Type=Byte, ColorInterp=Palette Overviews: 527x512, 211x205, 105x102, 53x51 Color Table (RGB with 256 entries)
Thanks to the -outsize option, I can create a TIFF file containing only the first overview :
$ gdal_translate -outsize 25% 25% World.ozf2 World.tif Input file size is 2108, 2048 $ gdalinfo -noct World.tif Driver: GTiff/GeoTIFF Files: World.tif Size is 527, 512 Band 1 Block=527x15 Type=Byte, ColorInterp=Palette Color Table (RGB with 256 entries)
But I would like to keep the other overviews, so I add the COPY_SRC_OVERVIEW option :
$ gdal_translate -outsize 25% 25% -co COPY_SRC_OVERVIEWS=YES World.ozf2 World.tif Input file size is 2108, 2048 $ gdalinfo -noct World.tif Driver: GTiff/GeoTIFF Files: World.tif Size is 527, 512 Band 1 Block=527x15 Type=Byte, ColorInterp=Palette Color Table (RGB with 256 entries)
There are no overviews in the output file. I expected three overviews (211x205, 105x102, 53x51).
Same problem with the -srcwin option :
$ gdal_translate -srcwin 0 0 527 512 -co COPY_SRC_OVERVIEWS=YES World.ozf2 World.tifInput file size is 2108, 2048 $ gdalinfo -noct World.tif Driver: GTiff/GeoTIFF Files: World.tif Size is 527, 512 Band 1 Block=527x15 Type=Byte, ColorInterp=Palette Color Table (RGB with 256 entries)
No overviews in the output file.
Change History (2)
comment:1 by , 12 years ago
Type: | defect → enhancement |
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comment:2 by , 8 years ago
Resolution: | → wontfix |
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Status: | new → closed |
Closing this as wontfix. The use case of this ticket is not common enough for judging a special handling when -outsize fits exactly with some overview level.
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Yes as I explained in http://lists.osgeo.org/pipermail/gdal-dev/2011-January/027379.html this is the expected behaviour (from a developer point of view ;-)) due to the use of an intermediate VRT when using gdal_translate options.
The main purpose of that option was to be able to translate an uncompressed TIFF with overviews into a compressed TIFF without needing to recompute the overviews, which can be a slow (and lossy) operation when operating on compressed datasets.
I do not anticipate any progress on this unless the VRT format supports exposing source overviews, which at first thought, doesn't seen obvious at all especially in the -outsize case. A naive but very natural implementation would create 4 overviews like the source dataset, each overview being 25% the size of the source overview...
Reclassifying as enhancement.
I've added a warning about this in the GTiff driver doc in r21530