[gdal-dev] corner coords in tif vs ecw

[kmayall]

I used gdal_translate to convert a geotiff to an ecw file.

C:\Program Files\FWTools2.4.7>gdal_translate -of ECW f:\test\mytif.tif
f:\test\myecw.ecw
Input file size is 2353, 2353
0...10...20...30...40...50...60...70...80...90...100 - done.

However, the corner coordinates are different between the two files.
The tiff uses values from the coordinate system, while the ecw seems to just
use the tile dimensions.
I'm not sure if there is something different in how the two formats store
that data, or if there was an option I didn't use.  Any insight is
appreciated.  gdalinfo results for the tif and ecw are below.

C:\Program Files\FWTools2.4.7>gdalinfo f:\gisdata\test\mytif.tif
Driver: GTiff/GeoTIFF
Files: f:\gisdata\test\mytif.tif
Size is 2353, 2353
Coordinate System is:
PROJCS["Bermuda_2000_National_Grid",
    GEOGCS["GCS_Bermuda_2000",
        DATUM["Bermuda_2000",
            SPHEROID["WGS_1984",6378137,298.257223563]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",32],
    PARAMETER["central_meridian",-64.75],
    PARAMETER["scale_factor",1],
    PARAMETER["false_easting",550000],
    PARAMETER["false_northing",100000],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]]]
Origin = (535999.787499999980000,129999.862499999990000)
Pixel Size = (0.425000000000000,-0.425000000000000)
Metadata:
  TIFFTAG_SOFTWARE=ERDAS IMAGINE
  TIFFTAG_XRESOLUTION=1
  TIFFTAG_YRESOLUTION=1
  TIFFTAG_RESOLUTIONUNIT=1 (unitless)
  AREA_OR_POINT=Area
Image Structure Metadata:
  INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left  (  535999.787,  129999.862) ( 64d53'54.96"W, 32d16'13.63"N)
Lower Left  (  535999.787,  128999.837) ( 64d53'54.90"W, 32d15'41.16"N)
Upper Right (  536999.813,  129999.862) ( 64d53'16.74"W, 32d16'13.67"N)
Lower Right (  536999.813,  128999.837) ( 64d53'16.70"W, 32d15'41.20"N)
Center      (  536499.800,  129499.850) ( 64d53'35.82"W, 32d15'57.42"N)
Band 1 Block=2353x8 Type=Byte, ColorInterp=Red
Band 2 Block=2353x8 Type=Byte, ColorInterp=Green
Band 3 Block=2353x8 Type=Byte, ColorInterp=Blue

C:\Program Files\FWTools2.4.7>gdalinfo f:\gisdata\test\myecw.ecw
Driver: ECW/ERMapper Compressed Wavelets
Files: f:\gisdata\test\myecw.ecw
       f:\gisdata\test\myecw.ecw.aux.xml
Size is 2353, 2353
Coordinate System is:
PROJCS["Bermuda_2000_National_Grid",
    GEOGCS["GCS_Bermuda_2000",
        DATUM["Bermuda_2000",
            SPHEROID["WGS_1984",6378137,298.257223563]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",32],
    PARAMETER["central_meridian",-64.75],
    PARAMETER["scale_factor",1],
    PARAMETER["false_easting",550000],
    PARAMETER["false_northing",100000],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]]]
Metadata:
  TIFFTAG_SOFTWARE=ERDAS IMAGINE
  TIFFTAG_XRESOLUTION=1
  TIFFTAG_YRESOLUTION=1
  TIFFTAG_RESOLUTIONUNIT=1 (unitless)
  AREA_OR_POINT=Area
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0, 2353.0)
Upper Right ( 2353.0,    0.0)
Lower Right ( 2353.0, 2353.0)
Center      ( 1176.5, 1176.5)
Band 1 Block=2353x1 Type=Byte, ColorInterp=Red
  Overviews: arbitrary
Band 2 Block=2353x1 Type=Byte, ColorInterp=Green
  Overviews: arbitrary
Band 3 Block=2353x1 Type=Byte, ColorInterp=Blue
  Overviews: arbitrary


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