[Qgis-developer] Plugin Georeference handle files with existing georeferencing information

[John C. Tull]

Hi Manuel,

I was hasty in my last response. I should have added that this was a raw tiff (no georeference) converted from a pdf map file.

> gdalinfo file.tiff

Driver: GTiff/GeoTIFF
Files: file.tiff
Size is 1275, 1651
Coordinate System is `'
Metadata:
  TIFFTAG_XRESOLUTION=150
  TIFFTAG_YRESOLUTION=150
  TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
Image Structure Metadata:
  COMPRESSION=LZW
  INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0, 1651.0)
Upper Right ( 1275.0,    0.0)
Lower Right ( 1275.0, 1651.0)
Center      (  637.5,  825.5)
Band 1 Block=1275x34 Type=Byte, ColorInterp=Red
Band 2 Block=1275x34 Type=Byte, ColorInterp=Green
Band 3 Block=1275x34 Type=Byte, ColorInterp=Blue

I attempted to shift this to both an epsg 4326 file and an epsg 26911. Neither would correctly reference. Here is the gdalinfo output from the utm-based file. The origin is well to the west of where it should be. The utm coordinates in my project display accurately, so I'm not sure what occurred.

gdalinfo Fletcher_Junction_Survey_sm8-09_modified.tif 
Driver: GTiff/GeoTIFF
Files: Fletcher_Junction_Survey_sm8-09_modified.tif
Size is 1287, 1660
Coordinate System is:
PROJCS["NAD83 / UTM zone 11N",
    GEOGCS["NAD83",
        DATUM["North_American_Datum_1983",
            SPHEROID["GRS 1980",6378137,298.2572221010002,
                AUTHORITY["EPSG","7019"]],
            AUTHORITY["EPSG","6269"]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433],
        AUTHORITY["EPSG","4269"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",-117],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AUTHORITY["EPSG","26911"]]
Origin = (-527554.436887833755463,4318930.947868065908551)
Pixel Size = (3.003000362929897,-3.003000362929897)
Metadata:
  AREA_OR_POINT=Area
Image Structure Metadata:
  COMPRESSION=LZW
  INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left  ( -527554.437, 4318930.948) (128d45'11.95"W, 38d25'28.03"N)
Lower Left  ( -527554.437, 4313945.967) (128d44'45.95"W, 38d22'49.70"N)
Upper Right ( -523689.575, 4318930.948) (128d42'35.89"W, 38d25'43.88"N)
Lower Right ( -523689.575, 4313945.967) (128d42'9.98"W, 38d23'5.52"N)
Center      ( -525622.006, 4316438.458) (128d43'40.94"W, 38d24'16.79"N)
Band 1 Block=1287x2 Type=Byte, ColorInterp=Red
  NoData Value=0
Band 2 Block=1287x2 Type=Byte, ColorInterp=Green
  NoData Value=0
Band 3 Block=1287x2 Type=Byte, ColorInterp=Blue
  NoData Value=0


Regards,
John

On Jul 12, 2010, at 11:44 AM, Manuel Massing wrote:

> Hi John,
> 
> it could be that you are indeed experiencing the issues which arise
> when opening files with preexisting georeference/geotransform information,
> 
> It would be helpful if you could check if your input files contain any
> georeferences or a geotransform (e.g. by using
> gdalinfo, or by displaying the raster properties within qgis).
> 
> thanks,
> 
> 	Manuel