HI all,<br><br>I am trying to understand how coordinate information is stored in a GeoTiff file, specifically the origin (UL corner) of the image. I have a few images which clearly have wrong origins, so they do not display correctly. Both ArcGIS and GDAL report incorrect origins.<br>
<br>Initially I thought that the world files for the images were at fault, however, they look totally fine. Here is an example -- notice really large X-coord of origin as reported by gdalinfo:<br><div style="margin-left: 40px;">
<span style="font-family: courier new,monospace;">> gdalinfo 1km177310505102008GROUPEALTA.tif</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">Driver: GTiff/GeoTIFF</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">Files: 1km177310505102008GROUPEALTA.tif</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> 1km177310505102008GROUPEALTA.tfw</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">Size is 5000, 5000</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">Coordinate System is:</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">PROJCS["UTM Zone 17N",</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> GEOGCS["NAD83_CSRS_1",</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> DATUM["NAD83_CSRS_1",</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> SPHEROID["GRS 1980",6378137,298.2572220960423]],</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> PRIMEM["Greenwich",0],</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> UNIT["degree",0.0174532925199433]],</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> PROJECTION["Transverse_Mercator"],</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> PARAMETER["latitude_of_origin",0],</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> PARAMETER["central_meridian",-81],</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> PARAMETER["scale_factor",0.9996],</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> PARAMETER["false_easting",500000],</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> PARAMETER["false_northing",0],</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> UNIT["metre",1,</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> AUTHORITY["EPSG","9001"]]]</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">Origin = (5051999.800000000700000,5052000.000000000000000)</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">Pixel Size = (0.200000000000000,-0.200000000000000)</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">Metadata:</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> TIFFTAG_SOFTWARE=Adobe Photoshop CS2 Windows</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> TIFFTAG_DATETIME=2008:12:30 16:08:24</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> TIFFTAG_XRESOLUTION=72</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> TIFFTAG_YRESOLUTION=72</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> AREA_OR_POINT=Area</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">Image Structure Metadata:</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> INTERLEAVE=PIXEL</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">Corner Coordinates:</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">Upper Left ( 5051999.800, 5052000.000) ( 34d52'42.64"W, 34d45'16.48"N)</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">Lower Left ( 5051999.800, 5051000.000) ( 34d52'48.38"W, 34d44'52.51"N)</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">Upper Right ( 5052999.800, 5052000.000) ( 34d52'28.05"W, 34d45'5.78"N)</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">Lower Right ( 5052999.800, 5051000.000) ( 34d52'33.77"W, 34d44'41.81"N)</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">Center ( 5052499.800, 5051500.000) ( 34d52'38.21"W, 34d44'59.14"N)</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">Band 1 Block=5000x1 Type=Byte, ColorInterp=Red</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">Band 2 Block=5000x1 Type=Byte, ColorInterp=Green</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">Band 3 Block=5000x1 Type=Byte, ColorInterp=Blue</span><br>
<br></div>The world file looks fine to me, and it has correct origin info (X-coord):<br><div style="margin-left: 40px; font-family: courier new,monospace;">> type 1km177310505102008GROUPEALTA.tfw<br>0.200000<br>0.000000<br>
0.000000<br>-0.200000<br>731000.100000<br>5051999.900000<br></div><br>Even if I rename the TFW file, gdalinfo still reports the same incorrect origin, so it must be stored in a GeoTiff tag, I guess? If so, how do I override and correct this info on an image? Also, does a world file not have a higher priority than a built-in tag value?<br>
<br>Thank you,<br>Aleksey<br>