Hi,
A better reference file can be created by materializing the VRT. The one
created by gdal_create has the same raster values on all the pixels but the
materialized one contains the same original image data. Maybe in your test case
with uncompressed outputs the difference is not so big, but please test it
anyway.
gdal_translate -of GTiff -co tiled=yes -co compress=LZW input.vrt output.tif
gdaladdo -ro output.tif
What is the difference in speed now? Ten times slower performance with vrt
feels quite a lot.
-Jukka Rahkonen-
Lähettäjä: gdal-dev <gdal-dev-boun...@lists.osgeo.org> Puolesta Denis Rykov via
gdal-dev
Lähetetty: keskiviikko 5. kesäkuuta 2024 4.36
Vastaanottaja: gdal dev <gdal-dev@lists.osgeo.org>
Aihe: [gdal-dev] gdaladdo slowness for VRTs
Hi,
I spotted a slow calculation of overviews and I'm wondering what could be the
reason.
$ gdal_create in.tif -if 20240602_230818_SN26_RR_VISUAL_MS.vrt
$ time gdaladdo -ro in.tif
gdaladdo -ro in.tif 4,25s user 6,23s system 34% cpu 30,623 total
But on the file of the same size and num of bands but VRT it takes much more
time:
$ time gdaladdo -ro 20240602_230818_SN26_RR_VISUAL_MS.vrt
gdaladdo -ro 55,36s user 5,06s system 44% cpu 2:14,79 total
Here is the output of gdalinfo of the VRT:
$ gdalinfo 20240602_230818_SN26_RR_VISUAL_MS.vrt
Driver: VRT/Virtual Raster
Files: 20240602_230818_SN26_RR_VISUAL_MS.vrt
20240602_230818_SN26_RR_VISUAL_MS_340_5020.tif
20240602_230818_SN26_RR_VISUAL_MS_340_5040.tif
20240602_230818_SN26_RR_VISUAL_MS_360_5020.tif
20240602_230818_SN26_RR_VISUAL_MS_360_5040.tif
20240602_230818_SN26_RR_VISUAL_MS_360_5060.tif
Size is 20779, 46754
Coordinate System is:
PROJCRS["WGS 84 / UTM zone 59S",
BASEGEOGCRS["WGS 84",
DATUM["World Geodetic System 1984",
ELLIPSOID["WGS 84",6378137,298.257223563,
LENGTHUNIT["metre",1]]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
ID["EPSG",4326]],
CONVERSION["UTM zone 59S",
METHOD["Transverse Mercator",
ID["EPSG",9807]],
PARAMETER["Latitude of natural origin",0,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8801]],
PARAMETER["Longitude of natural origin",171,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8802]],
PARAMETER["Scale factor at natural origin",0.9996,
SCALEUNIT["unity",1],
ID["EPSG",8805]],
PARAMETER["False easting",500000,
LENGTHUNIT["metre",1],
ID["EPSG",8806]],
PARAMETER["False northing",10000000,
LENGTHUNIT["metre",1],
ID["EPSG",8807]]],
CS[Cartesian,2],
AXIS["easting",east,
ORDER[1],
LENGTHUNIT["metre",1]],
AXIS["northing",north,
ORDER[2],
LENGTHUNIT["metre",1]],
ID["EPSG",32759]]
Data axis to CRS axis mapping: 1,2
Origin = (353999.799999999988358,5068000.629999999888241)
Pixel Size = (0.770000000000000,-0.770000000000000)
Corner Coordinates:
Upper Left ( 353999.800, 5068000.630) (169d 9'45.50"E, 44d31'35.55"S)
Lower Left ( 353999.800, 5032000.050) (169d 9' 8.52"E, 44d51' 1.68"S)
Upper Right ( 369999.630, 5068000.630) (169d21'50.06"E, 44d31'46.58"S)
Lower Right ( 369999.630, 5032000.050) (169d21'17.12"E, 44d51'12.83"S)
Center ( 361999.715, 5050000.340) (169d15'30.36"E, 44d41'24.33"S)
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=Undefined
NoData Value=0
And gdalinfo output for one of the underlying rasters:
gdalinfo 20240602_230818_SN26_RR_VISUAL_MS_360_5040.tif
Driver: GTiff/GeoTIFF
Files: 20240602_230818_SN26_RR_VISUAL_MS_360_5040.tif
Size is 10390, 25974
Coordinate System is:
PROJCRS["WGS 84 / UTM zone 59S",
BASEGEOGCRS["WGS 84",
DATUM["World Geodetic System 1984",
ELLIPSOID["WGS 84",6378137,298.257223563,
LENGTHUNIT["metre",1]]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
ID["EPSG",4326]],
CONVERSION["UTM zone 59S",
METHOD["Transverse Mercator",
ID["EPSG",9807]],
PARAMETER["Latitude of natural origin",0,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8801]],
PARAMETER["Longitude of natural origin",171,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8802]],
PARAMETER["Scale factor at natural origin",0.9996,
SCALEUNIT["unity",1],
ID["EPSG",8805]],
PARAMETER["False easting",500000,
LENGTHUNIT["metre",1],
ID["EPSG",8806]],
PARAMETER["False northing",10000000,
LENGTHUNIT["metre",1],
ID["EPSG",8807]]],
CS[Cartesian,2],
AXIS["(E)",east,
ORDER[1],
LENGTHUNIT["metre",1]],
AXIS["(N)",north,
ORDER[2],
LENGTHUNIT["metre",1]],
USAGE[
SCOPE["Engineering survey, topographic mapping."],
AREA["Between 168°E and 174°E, southern hemisphere between 80°S and
equator, onshore and offshore. New Zealand."],
BBOX[-80,168,0,174]],
ID["EPSG",32759]]
Data axis to CRS axis mapping: 1,2
Origin = (359999.640000000013970,5060000.330000000074506)
Pixel Size = (0.770000000000000,-0.770000000000000)
Metadata:
AREA_OR_POINT=Area
Image Structure Metadata:
COMPRESSION=LZW
INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left ( 359999.640, 5060000.330) (169d14' 9.36"E, 44d35'59.00"S)
Lower Left ( 359999.640, 5040000.350) (169d13'49.66"E, 44d46'46.86"S)
Upper Right ( 367999.940, 5060000.330) (169d20'12.11"E, 44d36' 4.44"S)
Lower Right ( 367999.940, 5040000.350) (169d19'53.53"E, 44d46'52.34"S)
Center ( 363999.790, 5050000.340) (169d17' 1.19"E, 44d41'25.70"S)
Band 1 Block=256x256 Type=Byte, ColorInterp=Red
NoData Value=0
Band 2 Block=256x256 Type=Byte, ColorInterp=Green
NoData Value=0
Band 3 Block=256x256 Type=Byte, ColorInterp=Blue
NoData Value=0
Band 4 Block=256x256 Type=Byte, ColorInterp=Undefined
NoData Value=0
What could be the reason for such a significant difference?
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