Le mercredi 24 décembre 2014 11:19:14, Simen Langseth a écrit : > Dear Even Rouault > > Thanks for your answer. > > When I used more than 1024 mb for sub-sampling an image, strangely with in > few minutes, a completely black image is produced.
Hum, I'm just fixing a but wher putting more in -wm caused issue but it was very specific : http://trac.osgeo.org/gdal/ticket/5789 > Using 1024 is not sufficient because my input file is around 300GB. Eh, read again what I wrote : "putting more warp memory will not necessarily need to more performance". -wm is the size of individual chunks that will be warped. Working on very big chunks is actually detrimental if you want to use -multi since there will be less opportunity to parallelize I/O and CPU bound operations. If not already done, you'll get probably much more performance by for example ensuring you output to a tiled GeoTIFF, by adding -co TILED=YES > I could > not figure out the problem. I am also using '-multi' parameter. > There is no problem if I do not use '-wm' and '-multi' parameters or just > use 1024 with '-wm' and '-multi' except very slowness. > > I hope you can help me. > > Simen > > > > On Wed, Dec 24, 2014 at 6:50 PM, Even Rouault <[email protected]> > > wrote: > > Le mercredi 24 décembre 2014 06:05:50, Simen Langseth a écrit : > > > What is the maximum '-wm' I can use with 64bit gdalwarp? > > > > Simen, > > > > Up to 9999 for 9999 MB. And if you want more, you have to specified the > > value > > in bytes instead of megabytes. > > But putting more warp memory will not necessarily need to more > > performance, especially if you mosaic many small images into a big one. > > > > See > > > > https://trac.osgeo.org/gdal/wiki/UserDocs/GdalWarp#WillincreasingRAMincre > > asethespeedofgdalwarp > > > > Even > > > > -- > > Spatialys - Geospatial professional services > > http://www.spatialys.com -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
