I have a piece of C++ code that is clipping regions from a very large (roughly 90,000 x 100,000 pixels, 11G compressed) Float32 gray-scale single band image and writing each as a separate GeoTiff (with LZW compression). In the sample that I've run, I've clipped four different regions. gdalinfo can read and provide a description of all four, however for only two of the images does gdalinfo provide summary statistics. I can open two of the images in qgis, while the two that fail to produce summary statistics cause qgis to hang when I try to open them. The two that I can open have block sizes of 247x8 (image size 247,311) and 583x3 (image size 583,602) , while the two that fail have block size 1198x1 (image size 1198, 809) and block size 1444x1 (image size 1444, 1007). I'm not sure why the block size would have an impact, esp since the ones that fail are n x 1, which I would think would be the easier to read in less capable systems, but it's the only common factor I've found so far.
All four images display correctly in the Windows Photo Viewer (Win 7). I'm a bit reluctant to show the whole code since it would take quite a few lines to get the whole picture down to the gdal calls. The heart of the write is done using GDALRasterBand::RasterIO, though. At the moment I'm at a loss as to where to start looking for the problem. Any suggestions are most welcome. David Strip _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
