[Gdal-dev] GDAL, JasPer, JPEG2000 memory management plans?

[Brent Fraser]

Frank, Andrey (and others),

    I've done some experimenting with GDAL's JPEG2000 capabilities on Windows 2000.

    While I got good results with a small (2mb, 929 x 986 pixels, RGB) and medium (20 mb, 2961 x 2270, RGB) size files, I noticed memory management  problems with large (100 mb, 4482 x x9011, RGB) and huge (1 gb, 18595 x 19729, RGB) files.

    During the translation of the large 100 mb file, 1.4 gb of ram was eventually allocated (90% of it by the JasPer code), but it did successfully finish after about 20 min.

    With the huge 1 gb tif file, GDAL_translate appears to allocate about 1 gb during the reading of the original tif file and attemps to allocate another 1 gb (in the Jasper code) just before starting to compress.  The second memory allocation fails on my computer (Windows 2000) even though I've got my virtual memory set to the maximum of 4 gb.

    Are there any enhancements that could be done to GDAL to reduce the amount of memory used?  I realize that wavelet compression (or at least the implementation in JasPer) may not lend itself to efficient memory use, and that GDAL's integration of JasPer is fairly new, but I thought I would get my request in early!

FYI, here's an example of my command line for the translation: 
    gdal_translate -of JPEG2000 -co "FORMAT=JP2" -co "rate=0.05" small.tif small.jp2

Thanks and keep up the good work!

Brent Fraser
GeoAnalytic Inc.
Tel:(403) 213-2700
bfraser at geoanalytic.com
www.geoanalytic.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/gdal-dev/attachments/20030507/a6dc9c84/attachment.html