Hi Even,
Thanks for getting back to me. I'm a little rusty with GDAL; it has
probably been 5+ years since I last used it.
I can confirm my QGIS install version (OSGEO4W) does have the JP2ECW
driver (`gdalinfo --formats`).
I'm using the Python GDAL build from
https://www.lfd.uci.edu/~gohlke/pythonlibs/#gdal - doesn't say it
includes JP2ECW. I only have access to that GDAL build via Python but
haven't managed to figure out what the Python API equivalent of
"gdalinfo --formats" is (assuming there is one).
I don't seem to be able to force JP2OpenJPEG on the OSGeo4W one.
gdalinfo --config GDAL_SKIP JP2ECW FILENAME.jp2 = uses the MrSID driver
gdalinfo --config GDAL_SKIP JP2ECW --config GDAL_SKIP JP2MrSID
FILENAME.jp2 = Goes back to JP2ECW
(Doesn't support the -if flag).
But I found `gdal.Info("FILENAME.jp2")` on the Python version, and that
does use the JP2 OpenJPEG driver. No tile information on there:
Driver: JP2OpenJPEG/JPEG-2000 driver based on OpenJPEG library
...
Image Structure Metadata:
INTERLEAVE=PIXEL
...
Band 1 Block=1024x1024 Type=Byte, ColorInterp=Red
Overviews: 66000x124000, 33000x62000, 16500x31000, 8250x15500,
4125x7750, 2063x3875, 1032x1938, 516x969, 258x485, 129x243, 65x122
Overviews: arbitrary
Image Structure Metadata:
COMPRESSION=JPEG2000
...
I can't help but notice the block size and overview levels are reporting
different info compared to the JP2ECW output (ECW one has different
rounding <= 2062*3875):
Band 1 Block=256x256 Type=Byte, ColorInterp=Red
Description = Red
Overviews: 66000x124000, 33000x62000, 16500x31000, 8250x15500,
4125x7750, 2062
x3875, 1031x1937, 515x968, 257x484
and JP2MrSID for comparison:
Band 1 Block=1024x128 Type=Byte, ColorInterp=Red
Min=168.000 Max=255.000
Minimum=168.000, Maximum=255.000, Mean=243.359, StdDev=16.164
Overviews: 66000x124000, 33000x62000, 16500x31000, 8250x15500,
4125x7750, 2063
x3875, 1032x1938, 516x969, 258x485, 129x243, 65x122, 33x61
Metadata:
STATISTICS_APPROXIMATE=YES
STATISTICS_MAXIMUM=255
STATISTICS_MEAN=243.35889029004
STATISTICS_MINIMUM=168
STATISTICS_STDDEV=16.164314681862
STATISTICS_VALID_PERCENT=100
All three report different Overview levels too. Odd but no idea if it is
pertinent to this problem.
Cheers,
Jonathan
p.s. I was looking for Python API docs but it seems there aren't any.
This page:
https://pypi.org/project/GDAL/#usage - has a link to
http://www.gdal.org/gdal_tutorial.html, but that's a 404. I think it
wants to be: https://gdal.org/tutorials/index.html
On 2020-08-09 11:14, Even Rouault wrote:
Jonathan,
The GDAL build that comes with rasterio must have only JP2OpenJPEG
enabled (the error with opj_decode() comes from that driver), whereas
the GDAL build in QGIS has also JP2ECW, which is used in priority.
The file is large. It would be interesting to know if it is tiled. If
you do "gdalinfo --format FILENAME.jp2 --config GDAL_SKIP JP2ECW", and
look at the beginning of the output, you should see lines like
OPENJPEG: nTileW = XXXX
OPENJPEG: nTileH = XXXX
which values are reported ?
If it is tiled (values <= 2048 let's say), this should normally work.
Openjpeg will have more difficulties with single-tile JPEG2000 files,
although latest versions (2.3.1) have seen improvements in that regard
Even
--
Spatialys - Geospatial professional services
http://www.spatialys.com
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