Do you mean gdal_translate -te -13813007 5569641 -13809113 5572598 srtm_merged_3857.vrt my_subwindow.tif --config GDAL_CACHEMAX 800
? On Thu, Jun 11, 2015 at 3:08 PM, Eli Adam <[email protected]> wrote: > On Thu, Jun 11, 2015 at 2:38 PM, Ari Simmons <[email protected]> > wrote: > > One notably huge difference is that there is a huge jump in pixel size > (from > > 0.000833333333323 to 205.686440189378940)... > > > > ah, duh. Unit change. > > > > On Thu, Jun 11, 2015 at 2:26 PM, Ari Simmons <[email protected]> > wrote: > >> > >> I am experimenting with using 'gdalwarp' on a .vrt (first time), but I'm > >> not sure what I'm doing wrong. I've been running this: > >> > >> >> gdalwarp -s_srs EPSG:4326 -t_srs EPSG:3857 -r bilinear -of VRT > >> >> merged.vrt srtm_merged_3857.vrt > >> > >> and it processes fast (far far *too fast* for this global file) and > >> returns > > That is the right speed (~0 seconds) and disk space (~0MB). That is > because it doesn't actually do anything except write down notes of > what it would have done (and will do in the future if you ask for it). > I like testing large VRT files by outputting a subwindow tif like > this: > > gdal_translate -13813007 5569641 -13809113 5572598 > srtm_merged_3857.vrt my_subwindow.tif --config GDAL_CACHEMAX 800 > > If things look good on the subwindow, then it is time for all the I/O > waiting, processor cycles, and storage space. Evaluating a few > places, especially where tiles come together can find things early > without all the wait. > > HTH, Eli > > >> > >> >> Creating output file that is 194835P X 479814L. > >> >> Processing input file merged.vrt > >> >> Using internal nodata values (eg. 0) for image merged.vrt > >> > >> The return .vrt file definitely doesn't appear right...a quick look at > the > >> returned file: > >> > >> input: > >> > >> Size is 432000, 208800 > >> Coordinate System is: > >> GEOGCS["WGS 84", > >> DATUM["WGS_1984", > >> SPHEROID["WGS 84",6378137,298.257223563, > >> AUTHORITY["EPSG","7030"]], > >> AUTHORITY["EPSG","6326"]], > >> PRIMEM["Greenwich",0], > >> UNIT["degree",0.0174532925199433], > >> AUTHORITY["EPSG","4326"]] > >> Origin = (-180.000416666666670,84.000416666666666) > >> Pixel Size = (0.000833333333323,-0.000833333333323) > >> Corner Coordinates: > >> Upper Left (-180.0004167, 84.0004167) (180d 0' 1.50"W, 84d 0' 1.50"N) > >> Lower Left (-180.0004167, -89.9995833) (180d 0' 1.50"W, 89d59'58.50"S) > >> Upper Right ( 179.9995833, 84.0004167) (179d59'58.50"E, 84d 0' 1.50"N) > >> Lower Right ( 179.9995833, -89.9995833) (179d59'58.50"E, 89d59'58.50"S) > >> Center ( -0.0004167, -2.9995833) ( 0d 0' 1.50"W, 2d59'58.50"S) > >> Band 1 Block=128x128 Type=Int16, ColorInterp=Gray > >> NoData Value=0 > >> Overviews: 216000x104400, 108000x52200, 54000x26100, 27000x13050, > >> 13500x6525, > >> 6750x3263, 3375x1632, 1688x816, 844x408, 422x204 > >> > >> and output file: > >> > >> Size is 193861, 479814 > >> Coordinate System is: > >> PROJCS["WGS 84 / Pseudo-Mercator", > >> GEOGCS["WGS 84", > >> DATUM["WGS_1984", > >> SPHEROID["WGS 84",6378137,298.257223563, > >> AUTHORITY["EPSG","7030"]], > >> AUTHORITY["EPSG","6326"]], > >> PRIMEM["Greenwich",0, > >> AUTHORITY["EPSG","8901"]], > >> UNIT["degree",0.0174532925199433, > >> AUTHORITY["EPSG","9122"]], > >> AUTHORITY["EPSG","4326"]], > >> PROJECTION["Mercator_1SP"], > >> PARAMETER["central_meridian",0], > >> PARAMETER["scale_factor",1], > >> PARAMETER["false_easting",0], > >> PARAMETER["false_northing",0], > >> UNIT["metre",1, > >> AUTHORITY["EPSG","9001"]], > >> AXIS["X",EAST], > >> AXIS["Y",NORTH], > >> EXTENSION["PROJ4","+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 > +lon_0=0.0 > >> +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs"], > >> AUTHORITY["EPSG","3857"]] > >> Origin = (-19837179.642485119000000,18807657.848855246000000) > >> Pixel Size = (205.686440189378940,-205.686440189378940) > >> Corner Coordinates: > >> Upper Left (-19837179.642,18807657.849) (178d12' 1.50"W, 84d 0' 1.50"N) > >> Lower Left (-19837179.642,-79883575.764) (178d12' 1.50"W, > 89d59'58.50"S) > >> Upper Right (20037399.339,18807657.849) (179d59'56.47"E, 84d 0' 1.50"N) > >> Lower Right (20037399.339,-79883575.764) (179d59'56.47"E, 89d59'58.50"S) > >> Center ( 100109.848,-30537958.958) ( 0d53'57.49"E, 89d 2'43.78"S) > >> Band 1 Block=512x128 Type=Int16, ColorInterp=Gray > >> Overviews: 96931x239907, 48466x119954, 24233x59977, 12117x29989, > 6059x14995, > >> 3030x7498, 1515x3749, 758x1875, 379x938, 191x471 > >> > >> One notably huge difference is that there is a huge jump in pixel size > >> (from 0.000833333333323 to 205.686440189378940)... > > > > > > > > _______________________________________________ > > gdal-dev mailing list > > [email protected] > > http://lists.osgeo.org/mailman/listinfo/gdal-dev >
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