Dear Even Rouault Whether I use '-multi' or not, '-wm 1024' works, but '-wm 3024' does not work in my PC.
I re-tested it, and again with in a very few minutes, a completely black image is produced. Thanks for your support. On Wed, Dec 24, 2014 at 7:30 PM, Even Rouault <[email protected]> wrote: > 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
