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

[Brent Fraser]

MessageCarl,

   I thought that using some more JasPer parameters might improve my situation, but JasPer's doc didn't go into very much detail on parameters (and I wasn't looking forward to reading the JPEG2000 spec at this point in my investigation).

   Can you give me an example of the gdal_translate command line you use with tiling parameters?

Thanks!
Brent Fraser
  ----- Original Message ----- 
  From: Anderson, Carl 
  To: gdal-dev at remotesensing.org 
  Sent: Wednesday, May 07, 2003 12:42 PM
  Subject: RE: [Gdal-dev] GDAL, JasPer, JPEG2000 memory management plans?




  I have been having problems encoding 13001x13001 JEPG2000 images on a
  Linux 2.4.20 machine and a Solaris 2.7 machine using gdal_translate and jasper

  on each machine unless I use tiling, encoding  dies inside jasper at
      jpc_t1enc.c on line 349   (  assert(0)  )

  When I do use tiling the result is ok.


  RE memory management:

  what about an implementation of a "Row-based wavelet transform" as described in
  ITU-T Rec T.800 (2000 FCDV1.0) page 163. Downloadable from http://www.jpeg.org/public/fcd15444-1.pdf

  of course that is really a jasper issue not a gdal one, and it may already be in the jasper lib.



  Carl Anderson

   

  GIS Manager

  Fulton County E&CD

  404.730.8026

  carl.anderson at co.fulton.ga.us

   

    -----Original Message-----
    From: Brent Fraser [mailto:bfraser at geoanalytic.com] 
    Sent: Wednesday, May 07, 2003 2:11 PM
    To: gdal-dev
    Subject: [Gdal-dev] GDAL, JasPer, JPEG2000 memory management plans?


    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

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