There is a problem with the RECTIFY CLIP command where the GeoTIFF tags are not being written to the output Tiff file correctly. Instead of using the lower left corner of the clip coverage, RECTIFY CLIP is aligning the upper left corner of the clip image to the upper left corner of the input image. This causes the final image to appear in the wrong location in ArcGIS.
The problem does not appear in Workstation because the World file is used to spatially locate the RECTIFY CLIP image.
There are two solutions:
- Solution 1
Generate an intermediate image without the GeoTIFF information.
A) Rectify the image with the clip cover as previous:
RECTIFY oldimg.tif newimg.tif # # clipcov
B) Convert the image to another format, thus eliminating the GeoTIFF tag information (but retaining the World file):
CONVERTIMAGE newimg.tif nextimg.bmp BMP
C) Convert the image back to the TIFF format.
CONVERTIMAGE nextimg.bmp finalimg.tif TIFF
- Solution 2
Change the way ArcGIS processes internal georeferencing information.
There is a registry setting in Windows for ArcGIS that by default is set to read the GeoTIFF information over the World File. However, at the current time this setting can only be changed with the Registry Editor. Since there is a risk of inadvertently causing damage to the integrity of Microsoft Windows, ESRI is not responsible for any problems that arise from using the Registry Editor. The following information is provided with the understanding that the user assumes all risks if implemented. Please read the following warning before proceeding:
WARNING: This article contains instructions to make specific changes to essential parts of your operating system. If these specific changes are not done correctly, it may cause serious problems to your computer operating system and files. First, ESRI recommends that you make a complete backup of your system, including the registry, before implementing any of the specific changes. It is highly recommended that you consult with your IT/MIS department, or other qualified computer systems professional before proceeding. ESRI cannot guarantee that you can solve problems that result from incorrect use of the Registry Editor utility. Use the Registry Editor utility at your own risk. Note: your operating system and any subsequent service packs may effect these instructions. These instructions are subject to change without notice.
To have ArcGIS use the World File information in precedence over the GeoTIFF:
- Open the Registry Editor by selecting Start / Run
- Type 'regedit' in the Open: field and click OK. This will open the Registry Editor.
- In My Computer, open HKEY_LOCAL_MACHINE
- Open SOFTWARE
- Open ESRI
- Open Raster
- Open Preferences
- Double click on the "filepref.favor_world_file" entry.
- Type "true" in the Value Data: field. Click OK.
- Close the Registry Editor.
By default ArcGIS 8.x looks for raster georeferencing from within the file itself, rather than any associated World file. Changing the filepref.favor_world_file setting will cause ArcGIS to search for any associated World files before it looks internally to the raster file. In this case, the WorkStation RECTIFY command is incorrectly creating the internal georeferencing but correctly creating the world file and this is why this solution is applicable. For other rasters where the internal georeferencing is correct and there is an incorrect world file associated with the raster, simply delete those incorrect world files and the internal georeferencing will be read, like it used to when the registry setting was set to false.