I did originally use -dstalpha. I had dropped it when creating the geotiffs as I used PHOTOMETRIC=YCBCR as a creation option.
I'll try with -dstalpha and dropping the YCBCR. Is there a known issue with using the vrts inside a tileindex that makes it so slow? -- This is what I used to convert to tif gdalwarp -rpc -of vrt -overwrite -t_srs epsg:3857 -r cubic --config GDAL_CACHEMAX 500 -wm 500 $1 $1.vrt gdal_translate -of GTiff -co "TILED=YES" -co "JPEG_QUALITY=95" -co "COMPRESS=JPEG" -co "PHOTOMETRIC=YCBCR" $1.vrt $1.tif gdaladdo --config COMPRESS_OVERVIEW JPEG --config PHOTOMETRIC_OVERVIEW YCBCR --config INTERLEAVE_OVERVIEW PIXEL $1.tif 2 4 8 16 32 Mike On 6/17/12 12:38 PM, "Even Rouault" <even.roua...@mines-paris.org> wrote: >Le dimanche 17 juin 2012 18:24:29, Smith, Michael ERDC-RDE-CRREL-NH a >écrit : >> I have a large number of NITF JP2K files. These files have IGEOLO >>metadata >> to the second accuracy so reprojecting these images leads to poor >>results. >> The images also have rpc metadata and using the -rpc option in gdalwarp >> reprojects them quite well. These files are source epsg:4326 and need to >> be reprojected to epsg:3857 for display. >> >> I had orginally thought to just create a vrt for each ntf file with the >>rpc >> information but a tileindex of the vrts is dramatically slower to >>display >> in MapServer (for a 1:8000 scale area, from ~ 1 sec to over 10 min). It >> does reproject correctly though. Obviously not practical. >> >> I then thought to reproject the vrts to an actual format (geotiff). The >> problem is that the black bounds (which should be nodata but are just >>near >> black areas) get expanded and aren't handled even when using the >>nearblack >> utility on the resulting geotiffs. >> >> The best option (if possible) would seem to use the source nitf files >>but >> force gdal to use the rpc information to reproject (without having to go >> through the vrt process). Perhaps a CPL config option that could be set >> inside mapserver? > >Did you use the -dstalpha option of gdalwarp, so that the areas in the >reprojected image that are not part of the source image are marked with a >0 >alpha value ? -dstnodata could also do it. > >> >> Other suggestions are welcome. >> >> Mike >> >> -- >> Michael Smith >> michael.sm...@usace.army.mil >> US Army Corps >> Remote Sensing GIS/Center _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev