[Geotiff] Get one part out of the GeoTIFF Image

[StefanReisser at t-online.de]

Hello!

At first I want to thank everbody for their quick response...

However, I have another question. The following is the output of the
gdalinfo tool of both the GeoTIFF and the DEM.
How can I use the corner coordinates of the DEM to compute the
corresponding raster coordinates of the GeoTIFF?
And if the projection parameters are not the same, how can I overcome
this problem?

Kind regards,

Stefan

[root at localhost include]# gdalinfo /mnt/cdrom/L7_P46R26S00.TIF
Driver: GTiff/GeoTIFF
Size is 19242, 17442
Coordinate System is:
PROJCS["NAD27 / UTM zone 10N",
    GEOGCS["NAD27",
        DATUM["North_American_Datum_1927",
            SPHEROID["Clarke 1866",6378206.4,294.9786982138982,
                AUTHORITY["EPSG","7008"]],
            AUTHORITY["EPSG","6267"]],
        PRIMEM["Greenwich",0],
        UNIT["degree (supplier to define
representation)",0.01745329251994328],
        AUTHORITY["EPSG","4267"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",-123],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AUTHORITY["EPSG","26710"]]
Origin = (509375.000000,5522290.000000)
Pixel Size = (12.50000000,-12.50000000)
Metadata:
  TIFFTAG_XRESOLUTION=300
  TIFFTAG_YRESOLUTION=300
  TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
Corner Coordinates:
Upper Left  (  509375.000, 5522290.000)
Lower Left  (  509375.000, 5304265.000)
Upper Right (  749900.000, 5522290.000)
Lower Right (  749900.000, 5304265.000)
Center      (  629637.500, 5413277.500)
Band 1 Block=19242x1 Type=Byte, ColorInterp=Red
Band 2 Block=19242x1 Type=Byte, ColorInterp=Green
Band 3 Block=19242x1 Type=Byte, ColorInterp=Blue

[root at localhost include]# gdalinfo /root/q1826.dem
Driver: USGSDEM/USGS Optional ASCII DEM (and CDED)
Size is 974, 1406
Coordinate System is:
PROJCS["UTM Zone 10, Northern Hemisphere",
    GEOGCS["NAD27",
        DATUM["North_American_Datum_1927",
            SPHEROID["Clarke 1866",6378206.4,294.978698213898,
                AUTHORITY["EPSG","7008"]],
            TOWGS84[-3,142,183,0,0,0,0],
            AUTHORITY["EPSG","6267"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9108"]],
        AXIS["Lat",NORTH],
        AXIS["Long",EAST],
        AUTHORITY["EPSG","4267"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",-123],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0]]
Origin = (585735.000000,5191825.000000)
Pixel Size = (10.00000000,-10.00000000)
Corner Coordinates:
Upper Left  (  585735.000, 5191825.000)
Lower Left  (  585735.000, 5177765.000)
Upper Right (  595475.000, 5191825.000)
Lower Right (  595475.000, 5177765.000)
Center      (  590605.000, 5184795.000)
Band 1 Block=974x1406 Type=Float32, ColorInterp=Undefined
  NoData Value=-32767
  Unit Type: m