[gdal-dev] -unscale issue with multiband vrt

[Kyle Shannon]

Hi All,
I am running into an issue with unscaling a multiband raster.  I am creating a vrt from 5 xyz datasets.  I use the following command:

gdalbuildvrt -separate -srcnodata -9999 mmi.vrt csv\*

3 of the 5 rasters are of the lower 48 states of the US, the other 2 are only the western half.  gdalbuildvrt works good, and pads the eastern half of the US with nodata values of -9999 for the western rasters.  I have to scale all of the bands, so I edit the vrt and add <Scale>100</Scale> to each VRTRasterBand

This displays correctly in gdalinfo:

C:\Users\k\Desktop\mmi_tmp\vrt_test>gdalinfo -stats -nomd mmi.vrt
Driver: VRT/Virtual Raster
Files: mmi.vrt
       csv\2008.WUS.Xpgv.537.2475
       csv\2008.WUS.Xpgv.537.475
       csv\UShazard.20081231.pga.10pc50
       csv\UShazard.20081231.pga.2pc50
       csv\UShazard.20081231.pga.5pc50
Size is 1201, 509
Coordinate System is `'
Origin = (-125.025000000000010,50.024999999999999)
Pixel Size = (0.050000000000000,-0.050000000000000)
Corner Coordinates:
Upper Left  (-125.0250000,  50.0250000)
Lower Left  (-125.0250000,  24.5750000)
Upper Right ( -64.9750000,  50.0250000)
Lower Right ( -64.9750000,  24.5750000)
Center      ( -95.0000000,  37.3000000)
Band 1 Block=128x128 Type=Float32, ColorInterp=Undefined
  Min=0.100 Max=200.000
  Minimum=0.100, Maximum=200.000, Mean=10.363, StdDev=16.347
  NoData Value=-9999
  Offset: 0,   Scale:100
Band 2 Block=128x128 Type=Float32, ColorInterp=Undefined
  Min=0.100 Max=123.982
  Minimum=0.100, Maximum=123.982, Mean=4.866, StdDev=8.152
  NoData Value=-9999
  Offset: 0,   Scale:100
Band 3 Block=128x128 Type=Float32, ColorInterp=Undefined
  Min=0.005 Max=1.110
  Minimum=0.005, Maximum=1.110, Mean=0.041, StdDev=0.064
  NoData Value=-9999
  Offset: 0,   Scale:100
Band 4 Block=128x128 Type=Float32, ColorInterp=Undefined
  Min=0.005 Max=2.037
  Minimum=0.005, Maximum=2.037, Mean=0.103, StdDev=0.150
  NoData Value=-9999
  Offset: 0,   Scale:100
Band 5 Block=128x128 Type=Float32, ColorInterp=Undefined
  Min=0.005 Max=1.346
  Minimum=0.005, Maximum=1.346, Mean=0.063, StdDev=0.097
  NoData Value=-9999
  Offset: 0,   Scale:100

When I unscale the raster, the Full US bands do fine, but the no data value for the Western US Bands isn't respected and the nodata values are changed.  Am I missing something in my vrt?  Any thoughts.

C:\Users\k\Desktop\mmi_tmp\vrt_test>gdal_translate -unscale mmi.vrt mmi.tif
Input file size is 1201, 509
0...10...20...30...40...50...60...70...80...90...100 - done.

C:\Users\k\Desktop\mmi_tmp\vrt_test>gdalinfo -nomd -stats mmi.tif
Driver: GTiff/GeoTIFF
Files: mmi.tif
Size is 1201, 509
Coordinate System is `'
Origin = (-125.025000000000010,50.024999999999999)
Pixel Size = (0.050000000000000,-0.050000000000000)
Corner Coordinates:
Upper Left  (-125.0250000,  50.0250000)
Lower Left  (-125.0250000,  24.5750000)
Upper Right ( -64.9750000,  50.0250000)
Lower Right ( -64.9750000,  24.5750000)
Center      ( -95.0000000,  37.3000000)
Band 1 Block=1201x1 Type=Float32, ColorInterp=Gray
  Minimum=-999900.000, Maximum=20000.000, Mean=-582357.045, StdDev=493551.313
  NoData Value=-9999
Band 2 Block=1201x1 Type=Float32, ColorInterp=Undefined
  Minimum=-999900.000, Maximum=12398.200, Mean=-582586.370, StdDev=493279.394
  NoData Value=-9999
Band 3 Block=1201x1 Type=Float32, ColorInterp=Undefined
  Minimum=0.500, Maximum=111.030, Mean=4.092, StdDev=6.447
  NoData Value=-9999
Band 4 Block=1201x1 Type=Float32, ColorInterp=Undefined
  Minimum=0.500, Maximum=203.720, Mean=10.284, StdDev=14.961
  NoData Value=-9999
Band 5 Block=1201x1 Type=Float32, ColorInterp=Undefined
  Minimum=0.500, Maximum=134.630, Mean=6.273, StdDev=9.686
  NoData Value=-9999



Kyle Shannon
Senior Software Engineer
GCS Research
Office 406-532-3254 * Direct 406-541-3276
kshannon at gcs-research.com<mailto:kshannon at gcs-research.com> * www.gcs-research.com<http://www.gcs-research.com/>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/gdal-dev/attachments/20111207/d0704961/attachment.html