Selon Aleksey Naumov <[email protected]>: With GDALSetGeoTransform() API, you can also modify in-place the geotransform matrix of an existing geotiff. The geotransform can be obtained from the world file with GDALLoadWorldFile() for example.
> Even, > > Thank you for explaining about tags in GeoTiff, I did not realize that have > priority over the world file. Your solution of using PROFILE=BASELINE works, > however it also truncates some useful tags, such as the coordinate system. I > could put the coordinate system back with -a_srs, but is there a way to > selectively delete certain tags froma GeoTiff (I suppose while re-creating > it, not in-place)? > > Or, is there a way to at least see the tags? Looked briefly at "tiffinfo" > and noticed output "Tag 33922: > 0.000000,0.000000,0.000000,5051999.800000,5052000.000000,0.000000" which > looks to me like it's citing the origin coordinates. However, did not > investigate further so far... > > Best regards, > Aleksey > > On Thu, Oct 22, 2009 at 2:02 PM, Even Rouault > <[email protected]>wrote: > > > Selon Aleksey Naumov <[email protected]>: > > > > GDAL GeoTIFF driver always use the GeoTIFF tag when it is found. Worldfiles > > are > > only used when no GeoTIFF tag exists. > > > > One way of achieving what you want to do is to produce a clone of your > > original > > GeoTIFF without the geotiff tag by using the PROFILE=BASELINE creation > > option. > > > > For example : > > gdal_translate 1km177310505102008GROUPEALTA.tif > > 1km177310505102008GROUPEALTA_nogeotifftag.tif -co PROFILE=BASELINE > > > > and then rename your worldfile to > > 1km177310505102008GROUPEALTA_nogeotifftag.wld > > > > > HI all, > > > > > > 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. > > > > > > 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: > > > > gdalinfo 1km177310505102008GROUPEALTA.tif > > > Driver: GTiff/GeoTIFF > > > Files: 1km177310505102008GROUPEALTA.tif > > > 1km177310505102008GROUPEALTA.tfw > > > Size is 5000, 5000 > > > Coordinate System is: > > > PROJCS["UTM Zone 17N", > > > GEOGCS["NAD83_CSRS_1", > > > DATUM["NAD83_CSRS_1", > > > SPHEROID["GRS 1980",6378137,298.2572220960423]], > > > PRIMEM["Greenwich",0], > > > UNIT["degree",0.0174532925199433]], > > > PROJECTION["Transverse_Mercator"], > > > PARAMETER["latitude_of_origin",0], > > > PARAMETER["central_meridian",-81], > > > PARAMETER["scale_factor",0.9996], > > > PARAMETER["false_easting",500000], > > > PARAMETER["false_northing",0], > > > UNIT["metre",1, > > > AUTHORITY["EPSG","9001"]]] > > > Origin = (5051999.800000000700000,5052000.000000000000000) > > > Pixel Size = (0.200000000000000,-0.200000000000000) > > > Metadata: > > > TIFFTAG_SOFTWARE=Adobe Photoshop CS2 Windows > > > TIFFTAG_DATETIME=2008:12:30 16:08:24 > > > TIFFTAG_XRESOLUTION=72 > > > TIFFTAG_YRESOLUTION=72 > > > TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch) > > > AREA_OR_POINT=Area > > > Image Structure Metadata: > > > INTERLEAVE=PIXEL > > > Corner Coordinates: > > > Upper Left ( 5051999.800, 5052000.000) ( 34d52'42.64"W, 34d45'16.48"N) > > > Lower Left ( 5051999.800, 5051000.000) ( 34d52'48.38"W, 34d44'52.51"N) > > > Upper Right ( 5052999.800, 5052000.000) ( 34d52'28.05"W, 34d45'5.78"N) > > > Lower Right ( 5052999.800, 5051000.000) ( 34d52'33.77"W, 34d44'41.81"N) > > > Center ( 5052499.800, 5051500.000) ( 34d52'38.21"W, 34d44'59.14"N) > > > Band 1 Block=5000x1 Type=Byte, ColorInterp=Red > > > Band 2 Block=5000x1 Type=Byte, ColorInterp=Green > > > Band 3 Block=5000x1 Type=Byte, ColorInterp=Blue > > > > > > The world file looks fine to me, and it has correct origin info > > (X-coord): > > > > type 1km177310505102008GROUPEALTA.tfw > > > 0.200000 > > > 0.000000 > > > 0.000000 > > > -0.200000 > > > 731000.100000 > > > 5051999.900000 > > > > > > 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? > > > > > > Thank you, > > > Aleksey > > > > > > > > > > _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
