Global Mapper v25.0

How to perform an affine transformation to a raster layer

Hi All,

I need to perform an affine transformation to a raster dem. To do this I have two control points with coordinates in two different systems. I tried with the "SHIFT - Transform Coordinates Based on File, but I'm not getting the expected results

Thanks in advance!



  • Affine transformation requires 3+ GCPs in each GRS.

  • Hi thikhpetr, thanks for you answer, I'm able to add a third point, the issue is I can't make the txt work, I have used the following format:

    // Shifting by inline GCPs


    GCP="(X-2.88;Y-1.43),377028.26,2091960.50,377025.38,2091959.07" \

    GCP="(X-1.67;Y-1.345),376481.54,2092765.57,376479.87,2092764.225" \


    I copied the format from the example in the help of Global Mapper, but for some reason, It doesn't work

    Thanks in advance


  • Hi, Corellana!

    My English leaves much to be desired. Just like Swahili.)) That's why it's a cartoon.

    Please note Error. This value must be <2!

  • Hey tikhpetr,

    Thanks a lot for this. But, what I'm looking is to use "SHIFT - Transform Coordinates Based on File", see images below

    But I'm looking to use this procedure as per the help file

    What for some reason I ignore it is not working...

    English is my second language too, much better in Spanish



  • But I don't understand what the problem is?