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I am creating an exercise for remote sensing students and would like to take an existing raster and remove the spatial reference from the file so that the students can practice using another image to orthorectify the first. I am using ArcGIS 10.

Any hints?

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    It depends on the file format of your image. Which files do you have (.tif .prj .tfw .aux.xml ...)?
    – Jens
    Commented May 29, 2013 at 15:44
  • It is a .tif file with an .aux.xml and .ovr. Commented May 29, 2013 at 15:48

4 Answers 4

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The fastest way to do this is to just delete the files that supply the spatial information related to the raster. If the image is stored as a tiff or you can just open up the folder it's stored in and delete all the files except the actual image. Then give that file to the students.

Looking at the image below, you would delete everything except the highlighted file, then distribute that.

enter image description here

I'm not certain how this would work with other raster formats that encapsulate the spatial information but you could always just export them to a tiff and then use this technique.

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    What about tiffs that store georeferencing information in GeoTiff tags in the actual tiff file, not in an external header file...?
    – user2856
    Commented May 30, 2013 at 3:41
  • I'm facing same problem but didn't found an ArcGIS solution. Is there any way to completely remove spatial references as well as extent coordinates from a GeoTiff?
    – Dave
    Commented Feb 20 at 14:55
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Another way that will completely strip any internal GeoTiff tags is by using the GDAL gdal_translate utility to convert the tif to a baseline tiff.

gdal_translate -co PROFILE=BASELINE in.tif out.tif

I realise you are using ArcGIS, so do I, but I have found GDAL to be another valuable tool in my geospatial software toolbox. Precompiled GDAL binaries can be downloaded from the GISInternals website.

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You can define the coordinate system as unknown by using the Define Projection tool. At the point of selecting the spatial reference, click on the little down arrow as indicated below and select clear.

Define Projection Tool

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    This will remove only the header, but not the coordinates themselves. Thus, you can try to find the correct coordinate system using the search method (brute force). Commented Jan 22, 2019 at 8:43
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This doesn't really answer the question since it doesn't use ArcGIS, but I found the most effective way to get rid of ALL the metadata in the EXIF tags and header of a GeoTIFF is to open the file in OpenCV then save it back to the same filename. OpenCV doesn't care about the exif, and just reads/writes the image data--bad if you care about the metadata, but good in this case.

Install opencv into a your python installation, virtual env with pip: pip install opencv-python. Conda has something similar.

Then just open the REPL (python in the command line). The only 'response' is True returned from imwrite().

>>> import cv2
>>> img = cv2.imread("ortho.tif")
>>> cv2.imwrite("ortho.tif", img)
True

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