James, I have reviewed nitfdataset.cpp and jpeg2000dataset.cpp (the JasPer driver) and I believe they are now compatible. That is, nitf now uses the /vsisubfile/ mechanism to operate on the jpeg2000 data stream and I see the JasPer driver now uses the VSI*L API needed to support the /vsisubfile/ mechanism.
However, most NITF files I have worked with that had jpeg2000 compression had single large compressed images, not many small tiles. The JasPer library does *not* provide an effective mechanism to read subareas so for a large image it tends to use as much as 10 times as much memory as would be needed to hold the decoded image. This makes it impractical for many geospatial applications. So I am still dubious about using it. Best regards, On Tue, Jan 26, 2010 at 9:12 AM, jim hopper <james.e.hop...@saic.com> wrote: > I read the item about lack of support for the J2K_SUBFILE mechanism using > jasper, and that it requires one of the commercial jpeg2000 drivers. Is > that still the case, or Is there a way to read jpeg2k nitfs with open source > jpeg2k libraries? > > Best jim > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev > -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, warmer...@pobox.com light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
