Hello<br><br>I am trying to rotate some GeoTiff images to be "North Up". When I run gdalwarp, it seems to eat the Geo Transform and other geo information.<br><br>The input image, which we'll call in.tif, has gdalinfo which looks like this:
<br>Driver: GTiff/GeoTIFF<br>Size is 27552, 30080<br>Coordinate System is:<br>GEOGCS["WGS 84",<br> DATUM["WGS_1984",<br> SPHEROID["WGS 84",6378137,298.2572235629972,<br> AUTHORITY["EPSG","7030"]],
<br> AUTHORITY["EPSG","6326"]],<br> PRIMEM["Greenwich",0],<br> UNIT["degree",0.0174532925199433],<br> AUTHORITY["EPSG","4326"]]<br>GeoTransform =
<br> <lon offset> <scale related> <nonzero rotation><br> <lat offset> <nonzero rotation> <scale related><br>Metadata:<br> tons of key-value pairs here.<br>Corner Coordinates:<br> listed in Lat/Long
<br><br>I'd like to have the same type of info in the output file, but with the rotations both zero (north up)<br><br>I tried:<br>gdalwarp in.tif out.tif<br><br>this results in the out.tif having no geo information, where gdalinfo outputs:
<br>Driver: GTiff/GeoTIFF<br>Size is 28141, 29577<br>Coordinate System is `'<br>Corner Coordinates:<br>Upper Left ( 0.0, 0.0)<br>Lower Left ( 0.0,29577.0)<br>Upper Right (28141.0, 0.0)<br>Lower Right (28141.0
,29577.0)<br>Center (14070.5,14788.5)<br>Band 1 Block=28141x1 Type=UInt16, ColorInterp=Gray<br><br>The problems as I see it are:<br>1) the coordinate system is gone in the output<br>2) the geo transform info is gone (including pixel scale and coordinate system offset)
<br>3) the corners are now expressed in pixel values (because of #2?)<br>4) all the metadata name/value pairs are gone<br><br>I tried many other variations, including specifying the target SRS values, and the source and target SRS, but I must confess I'm not sure I got this exactly right:
<br><br>gdalwarp -s_srs "+proj=latlong +datum=WGS84" -t_srs "+proj=latlong +datum=WGS84" -multi in.tif out.tif<br><br>I also tried adding "+north" to the target projection, which I saw on this list somewhere.
<br><br>Can anyone explain what I am doing wrong?<br><br>Thanks in advance!<br><br>Dan<br>