Le mercredi 21 mai 2014 15:34:40, David Fawcett a écrit : > Thank you Even. > > My input images came from an external source, so I have no control over > them. Are you suggesting that I tile the output? I don't see a creation > option of TILED=YES for OpenJPEG, it looks like I would have to use one of > the commercial libraries.
That's controlled by the BLOCKXSIZE and BLOCKYSIZE options. They imply tiling. But, by default, the openjpeg driver will tile the images with a tile size of 1024. On the contrary if you wanted a single-tile image, you would have to set BLOCKXSIZE and BLOCKYSIZE to the dimensions of the raster. > > David. > > > On Wed, May 21, 2014 at 7:21 AM, Even Rouault > > <even.roua...@mines-paris.org>wrote: > > Le mercredi 21 mai 2014 13:39:43, David Fawcett a écrit : > > > I am running gdal_translate to composite image tiles in a vrt and > > > reduce the output image size. I ran it at outsize 50% 50% and > > > received no warnings. When I bumped the outsize up to 75%, I got > > > quite a few > > > > warnings > > > > > like the one below. > > > > > > Warning 1: Right position of the decoded area (region_x1=5120) is > > > outside the image area (Xsiz=5000). > > > > > > This one gave no warnings: > > > gdal_translate img_index.vrt mpls50.jp2 -outsize 50% 50% -of > > > JP2OpenJPEG -co QUALITY=25 --config GDAL_MAX_DATASET_POOL_SIZE 10 > > > > > > This one produced warnings > > > gdal_translate img_index.vrt mpls7575.jp2 -outsize 75% 75% -of > > > > JP2OpenJPEG > > > > > -co QUALITY=75 --config GDAL_MAX_DATASET_POOL_SIZE 10 > > > > > > GDAL version is 1.10 > > > > > > Any suggestions on how to avoid the warnings? > > > > The warning come from the openjpeg library and suggests that the GDAL > > driver > > issue an invalid query extending over the right of an image. Which is > > indeed > > the case. I've just fixed it with http://trac.osgeo.org/gdal/ticket/5480 > > > > Looking at the openjpeg code, it looks like it should properly adjust the > > request to what expects the GDAL driver, so the end result should be OK. > > > > The fact that you get the warning at some subsampling ratio and not at > > others > > come from the fact that the overview dimensions are not the same and the > > GDAL > > driver adjusts its strategy how to work with openjpeg API (there's a tile > > API > > and a window API. The last one was the one that issued the warning) > > > > Another thing I wanted to mention is that the fact you ran into this > > issue reveals that your JPEG2000 images are mono-tile. Which is OK per > > se. The OpenJPEG library just doesn't work very efficiently with such > > images (basically > > even if you need one pixel, it will decode the whole image). Other > > JPEG2000 libraries are able to use other JPEG2000 mechanisms to operate > > more efficiently. > > > > > Thanks, > > > > > > David. > > > > -- > > Geospatial professional services > > http://even.rouault.free.fr/services.html -- Geospatial professional services http://even.rouault.free.fr/services.html _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
