<dl><dt>Hi,</dt></dl><br>Within gdalwarp where does using the higher quality option of -rc(cubic resampling) verses the default of nearest neighbour resampling have the greatest impact as far as quality and also as far as speed.
<br>Either<br>a.) running gdalwarp to mosaic a number of tiles together and at the same time reproject<br><dl><dt> i.e. gdalwarp.exe -wo SKIP_NOSOURCE=YES -s_srs EPSG:" + EPSG + " -t_srs EPSG:" + EPSG_wgs84 + " -rc -co tiled=yes -q " + inputFiles + " " + rasterFile
</dt><dt><br></dt><dt>b.) running gdalwarp to reduce the resolution but not changing the projection and not mosaicking<br></dt><dt> i.e. gdalwarp.exe -tr " + psx + " " + psy + " -s_srs EPSG:" + EPSG_wgs84 + " -t_srs EPSG:" + EPSG_wgs84 + " -rc -co tiled=yes -q " + rasterFile + " " + warpedSplitRasterFile
</dt></dl><br>Will it be faster to reduce resolution against a file via gdalwarp that has already been reduced and will the quality be the same? As an example:<br>1.) I mosaic a number of tiles at full resolution<br>2.) I reduce the mosaic from 1 by 1/2
<br>3a.) I reduce the mosaic from 1 by 1/4<br>3b.) I reduce the mosaic from 2 by 1/2<br><br>Between 3a and 3b will 3b be faster and will the quality be the same?<br><br>Any other suggestions on speeding up gdalwarp would be appreciated.
<br><br>Thanks,<br><dl><dd><br></dd></dl>-- <br>John J. Mitchell