Opened 14 years ago
Closed 14 years ago
#3531 closed defect (fixed)
Data is different depending on which band is requested
Reported by: | gbriggs | Owned by: | warmerdam |
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Priority: | normal | Milestone: | |
Component: | GDAL_Raster | Version: | svn-trunk |
Severity: | normal | Keywords: | JPIP JPIPKAK JPEG2000 |
Cc: |
Description
The following two commands give completely different data results for band 2 (the only band in the first case, and the middle band in the second):
gdal_translate.exe -of ENVI -b 2 -srcwin 27200 6450 501 451 jpip://216.150.195.220/JP2Server/Boulder_Foothills "C:\tmp\test_server_gdal_band2.img"
gdal_translate.exe -of ENVI -srcwin 27200 6450 501 451 jpip://216.150.195.220/JP2Server/Boulder_Foothills "C:\tmp\test_server_gdal_all_bands.img"
If you replace the -b 2 with -b 1, the results appear fine.
Change History (4)
comment:1 by , 14 years ago
comment:2 by , 14 years ago
Status: | new → assigned |
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I have had no problem reproducing serious issues with the situation described above.
comment:3 by , 14 years ago
The problem seems to be particular to handling of YCbCr images. Boulder_Foothills uses YCbCr as the underlying color space. If three bands are requested at once things are automatically transformed to RGB by the region decompressor. But if you request just band 2 then you get the "Cb" component which does not look like much.
Note that requesting band 1 was not *really* working - it is just that the Y component (intensity) is similar in appearance to any of the red, green or blue channel results.
I *think* the solution is to ensure that all components are fetched from the JPIP server for YCC color model images. I'm going to try this out.
comment:4 by , 14 years ago
Resolution: | → fixed |
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Status: | assigned → closed |
This strategy has been implemented in trunk (r19426) and appears to be working properly.
Replying to gbriggs:
I suspect this issue may be related to the fact that the region decompressor being utilized by JPIPKAK performs color conversions automatically. But I have not confirmed this.