id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc 5828,gdal_translate performance degrades on wide VRTs with PNG output,riveryeti,warmerdam,"I am using the commandline gdal_translate -of png -co ""ZLEVEL=1"" [filename].vrt [filename].png to translate two rasters from VRT to PNG (also converting to tiled tiff, but that works fine). Given two vrt ""rasters"" with sizes as follows: 191488,46080 (wide raster) 59392,201728 (tall raster) performance degrades to about 20bytes/sec on the wide raster when I hit about 30% processing (still at 30% + 1 dot 3 hours later). On the other hand, performance does not noticeably degrade when processing the tall raster, and the entire translation takes about 2-3 minutes. both vrts are built from 1024x1024 uncompressed TIFF tiles generated using otherwise the same methods/settings/projection/coordinate system/etc. gdalinfo from ""good"" vrt below (excluding file-list) vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv {{{ Size is 59392, 201728 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 = (-123.610326674747300,48.157496099385916) Pixel Size = (0.000001641647305,-0.000001100758214) Corner Coordinates: Upper Left (-123.6103267, 48.1574961) (123d36'37.18""W, 48d 9'26.99""N) Lower Left (-123.6103267, 47.9354423) (123d36'37.18""W, 47d56' 7.59""N) Upper Right (-123.5128260, 48.1574961) (123d30'46.17""W, 48d 9'26.99""N) Lower Right (-123.5128260, 47.9354423) (123d30'46.17""W, 47d56' 7.59""N) Center (-123.5615763, 48.0464692) (123d33'41.67""W, 48d 2'47.29""N) Band 1 Block=128x128 Type=Byte, ColorInterp=Red NoData Value=0 Band 2 Block=128x128 Type=Byte, ColorInterp=Green NoData Value=0 Band 3 Block=128x128 Type=Byte, ColorInterp=Blue NoData Value=0 Band 4 Block=128x128 Type=Byte, ColorInterp=Alpha NoData Value=0 }}} ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ gdalinfo from ""bad"" vrt below (excluding file-list) vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv {{{ Size is 191488, 46080 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 = (-123.657297355231180,48.158143203488351) Pixel Size = (0.000001374831964,-0.000000920181878) Corner Coordinates: Upper Left (-123.6572974, 48.1581432) (123d39'26.27""W, 48d 9'29.32""N) Lower Left (-123.6572974, 48.1157412) (123d39'26.27""W, 48d 6'56.67""N) Upper Right (-123.3940335, 48.1581432) (123d23'38.52""W, 48d 9'29.32""N) Lower Right (-123.3940335, 48.1157412) (123d23'38.52""W, 48d 6'56.67""N) Center (-123.5256654, 48.1369422) (123d31'32.40""W, 48d 8'12.99""N) Band 1 Block=128x128 Type=Byte, ColorInterp=Red NoData Value=0 Band 2 Block=128x128 Type=Byte, ColorInterp=Green NoData Value=0 Band 3 Block=128x128 Type=Byte, ColorInterp=Blue NoData Value=0 Band 4 Block=128x128 Type=Byte, ColorInterp=Alpha NoData Value=0 }}} ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ end. ",defect,closed,normal,2.0.0,GDAL_Raster,unspecified,normal,fixed,vrt,