Hello. Is there no gap or noises in image data generated by this method?
Regards. --- doug_newc...@fws.gov wrote: > > > > > >Hi Doug, > > >I finally tried your parameters and they did work > fine for me also. I > >had something like hundred geotiffs, 400 MB each, > and I was pushing > >them to bigtiff mosaic. I tried first with your > *.tif selection and then > >again by using a virtual raster file as source, > created from Mapserver > >tileindex shapefile with gdalbuildvrt. My Windows > computer was handling > >about 20 GB/hour with cubic resampling (-rc) this > time. Parameters > ?-wo "SKIP_NOSOURCE" --config "GDAL_CACHEMAX=500" > -wm=5000 > >seem to have a big influence on efficiency. I > wonder if there are some > >rules of thumb for selecting values of > GDAL_CACHEMAX and -wm. You said > >cachemax is good to be close to the maximum input > file size, how about > >-wm? > > >-Jukka Rahkonen- > > Jukka, > I remember seeing someone mention on the > mailing list ( Can't recall > who at the moment) that setting GDAL_CACHEMAX close > to the maximum size of > the input files gave the best performance. I did > try bumping GDAL_CACHEMAX > up to 2000 to see what would happen ( while dropping > -wm down to 3000, only > 6GB of RAM on that computer) , but none of the input > files I was processing > were larger than 500MB and I saw no increase in > performance. For the -wm > parameter, I just gave it the rest of the RAM > available on the computer, > and I did not benchmark while varying that number. > > Doug > > > Doug Newcomb > USFWS > Raleigh, NC > 919-856-4520 ext. 14 doug_newc...@fws.gov > --------------------------------------------------------------------------------------------------------- > > The opinions I express are my own and are not > representative of the > official policy of the U.S.Fish and Wildlife Service > or Dept. of the > Interior. Life is too short for undocumented, > proprietary data formats. > > > > > "Rahkonen Jukka" > > <jukka.rahko...@m > > mmtike.fi> > To > > <gdal-dev@lists.osgeo.org>, > 12/07/2009 05:06 > <doug_newc...@fws.gov> > AM > cc > > > > Subject > Re: CUDA > PyCUDA and GDAL > > > > > > > > > > > > > > > > > > <Doug_Newcomb <at> fws.gov> writes: > > > > Hi Folks,Here's the gdal command (gdal 1.6.2) I > used to merge ~3500 1 > meter NAIP > > quarter quads (uncompressed geotiff TIFF) in 3 UTM > projections into > one Bigtiff Image > > in the USGS Albers projection. It took about 15 > hours ( on a 3 year > old Intel Core2 > > Duo 64 bit Centos 5.3 Linux box with 6GB RAM) and > created an > uncompressed, tiled, > > bigtiff file of 485 GB. About 32 GB/hr. > > gdalwarp -t_srs "+proj=aea +lat_1=29.5+lat_2=45.5 > +lat_0=23.0 > +lon_0=-96 > > +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m > no_defs <>" > > -wo "SKIP_NOSOURCE" --config "GDAL_CACHEMAX=500" > -wm=5000 > > -co "TILED=YES" */*.tif > /biggis/albers/nc_naip2008.tif > > > > In the above command, -t_srs "+proj=aea > +lat_1=29.5 +lat_2=45.5 > +lat_0=23.0 > > +lon_0=-96 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 > +units=m no_defs > <>" > > indicates the target projection, -wo > "SKIP_NOSOURCE" don't write > > in areas for which there is no data for the > current file, > > --config "GDAL_CACHEMAX=500" set the cache memory > at 500MB ( set this > close > > to the maximum input file size), -wm=5000 set the > warp memory to > 5000MB , > > -co "TILED=YES" create a tiled tiff as output, > */*.tif, use all of the > tiffs > > in all of the subdirectories as input files ( in > this case there was > one > > directory for each of the 3 utm zones) , > /biggis/albers/nc_naip2008.tif, > > the output file name and location. > > > > Hi Doug, > > I finally tried your parameters and they did work > fine for me also. I > had something like hundred geotiffs, 400 MB each, > and I was pushing > them to bigtiff mosaic. I tried first with your > *.tif selection and then > again by using a virtual raster file as source, > created from Mapserver > tileindex shapefile with gdalbuildvrt. My Windows > computer was handling > about 20 GB/hour with cubic resampling (-rc) this > time. Parameters > -wo "SKIP_NOSOURCE" --config "GDAL_CACHEMAX=500" > -wm=5000 > seem to have a big influence on efficiency. I > wonder if there are some > rules of thumb for selecting values of GDAL_CACHEMAX > and -wm. You said > cachemax is good to be close to the maximum input > file size, how about > -wm? > > -Jukka Rahkonen- > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev
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