Hermann Peifer <peifer <at> gmx.eu> writes: > > Jukka wrote
> > > > Did you try to use gdalwarp also for the second step with -srcnodata value [value...]? I believe you did set > some NODATA value in step 1 for the intermediate images. > > > > -Jukka Rahkonen- > > I did. However, the main problem with gdalwarp is its performance. So my options seem to be: > > 1. > gdalwarping 1500 ASTER tiles in 1 run into a 4GB 100m raster output.tif > = 5-10 days processing (my best estimate) > > 2. > gdalwarping 1500 ASTER tiles 1-by-1 as an intermediate step, then > gdal_merge or gdal_translate to mosaic warped tiles into output.tif > = smaller or larger NODATA areas in output.tif, along tile borders Hi, I decided to do a little test in order to see how slow gdalwarp in in this kind of usage with my own imagery. My test plan was like this: 1. Original images: 199 JPEG2000 images, with 3 bands and 10000 by 10000 pixels each. All together make 28 gigabytes on disk in lossless JPEG2000 format, or 60 GB uncompressed. 2. My first try with gdalbuildvtr gdalbuildvrt -input_file_list gdalwarptest.txt gdalwarptest.vrt 0...10...20...30...40...50...60...70...80...90...100 - done. Nice experience, I like this little tool. 3. A try to make a tiff file from this virtual raster with gdalwarp gdalwarp -co BIGTIFF=YES -srcnodata 0 gdalwarptest.vrt gdalwarptest.tif Creating output file that is 182026P x 191204L. Gdalwarp has now been running for 27 hours. Process is taking 70 megabytes of memory and 5-15 percent of processor time. As a result I have now output tiff file that is very, very slowly growing in size. Now, after 27-hour run the filesize is 13 gigabytes. Judged by the filesize my new tiff file might be ready after 4-5 more days. However, I am not sure if this estimate is reliable. The gdalwarp status indicator is still showing just zero for me: Processing input file gdalwarptest.vrt. 0 Conclusion: Too slow to be useful with my settings. Question 1: Should it work this way? Question 2: If yes, is it worth trying to find the limits when it goes too slow and perhaps file a ticket? -Jukka Rahkonen- _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
