[Gdal-dev] gdaltindex reports no prj defined, gdalinfo disagrees, maybe

[Matt.Wilkie]

Hi,

I have an orthophoto tiff which gdaltindex ignores:

	It appears no georeferencing is available for
	`sheet9_east.tif', skipping.

gdalinfo reports a GCP projection but the corner coordinates at the end
appear to be in pixels instead of projected numbers. This image came with a
file called "sheet9_south.txg". I don't know what application created it.

Because I trust gdal more than most other programs I've used, I'm usually
inclined to think the gtiff metadata is incorrectly formatted. However
ArcCatalog (8.3) reads the projection. To be more precise it reports corner
coordinates -almost- the same as the GCP's reported by gdalinfo. 

To make things a little more confusing, the .txg file's corner coords are
out from both gdalinfo and arccatalog significantly (in the hundreds digit
place for northings, thousandth for eastings). 

Also the reported cell size differs between applications. 

Is all this variation normal? Is it just the gtiff equivalent of is a a
megabyte 1024k or 1000k? And more practically, what do I do about it? How
can I fix these images so both arccatalog and gdal utilities can use them?

If someone can tell me how to lop of the first few K of the file I can send
the head 'in situ' if you want to examine it directly. (the whole image is
540mb).

Thanks in advance,

-matt wilkie
--------------------------------------------
Geographic Information,
Information Management and Technology,
Yukon Department of Environment
10 Burns Road * Whitehorse, Yukon * Y1A 4Y9
867-667-8133 Tel * 867-393-7003 Fax
--------------------------------------------  

=== attached .xml is ArcCatalog's metadata report.

==== gdalinfo report:

Driver: GTiff/GeoTIFF
Size is 24402, 21002
Coordinate System is `'
GCP Projection = PROJCS["NAD83 / UTM zone
8N",GEOGCS["NAD83",DATUM["North_Americ an_Datum_1983",SPHEROID["GRS
1980",6378137,298.2572221010002,AUTHORITY["EPSG","7
019"]],AUTHORITY["EPSG","6269"]],PRIMEM["Greenwich",0],UNIT["degree",0.01745
3292
5199433],AUTHORITY["EPSG","4269"]],PROJECTION["Transverse_Mercator"],PARAMET
ER["
latitude_of_origin",0],PARAMETER["central_meridian",-135],PARAMETER["scale_f
acto
r",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],U
NIT[ "metre",1,AUTHORITY["EPSG","9001"]],AUTHORITY["EPSG","26908"]]
GCP[  0]: Id=1, Info=
          (0,0) -> (512595,6.66881e+006,0)
GCP[  1]: Id=2, Info=
          (24401,0) -> (523552,6.67417e+006,0)
GCP[  2]: Id=3, Info=
          (0,21001) -> (517213,6.65937e+006,0)
GCP[  3]: Id=4, Info=
          (24401,21001) -> (528170,6.66474e+006,0)
Metadata:
  TIFFTAG_IMAGEDESCRIPTION=Extracted from 'MOSAIC' using polygon '1'
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0,21002.0)
Upper Right (24402.0,    0.0)
Lower Right (24402.0,21002.0)
Center      (12201.0,10501.0)
Band 1 Block=24402x1 Type=Byte, ColorInterp=Gray


==== sheet9_south.txg:

Format: Tag Image File Format
Description: Extracted from 'MOSAIC' using polygon '1"
TIFF Version: 6.0
Compression type: None
Image type: 8 bit grayscale
Image type: 8-bit unsigned
Image size: 24402 columns by 22000 lines
Resolution: 0.500000 (column) by 0.500000 (line) m per cell
Coordinate system: Universal Transverse Mercator  Zone: 8 (W 138 to W 132)
Units: m
Corners:
   Upper Left:  507977.6685590000 E  6678234.67257800 N
  Upper Right:  518935.3834929950 E  6683600.57272852 N
   Lower Left:  512815.3787184680 E  6668355.57543236 N
  Lower Right:  523773.0936524630 E  6673721.47558288 N
  Note: Georeference control points are at outside edges of image.
        This is the upper left corner of the upper left cell,
        the upper right corner of the upper right cell, etc.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: sheet9_south.tif.xml
Type: application/octet-stream
Size: 7890 bytes
Desc: not available
Url : http://lists.osgeo.org/pipermail/gdal-dev/attachments/20031003/5a840814/sheet9_south.tif.obj