Matching 2 Images (Layers) With Selected Points

[skip671]

I have 2 images (maps).  One is a scale image from Google Maps.  The other is an historic map that is not to scale.  There are certain points of reference on each map that can be used to pull the historic map close to scale and provide reference to other points between the two maps.  Is there a way to link 2 images with "points" on each and transform one of the two base on the those links?

[Krikor]

(05-23-2023, 02:51 PM)skip671 Wrote: I have 2 images (maps).  One is a scale image from Google Maps.  The other is an historic map that is not to scale.  There are certain points of reference on each map that can be used to pull the historic map close to scale and provide reference to other points between the two maps.  Is there a way to link 2 images with "points" on each and transform one of the two base on the those links?

Maybe this could be useful : https://www.gimp-forum.net/Thread-sg-fit...ht=realing

[programmer_ceds]

(05-23-2023, 02:51 PM)skip671 Wrote: I have 2 images (maps).  One is a scale image from Google Maps.  The other is an historic map that is not to scale.  There are certain points of reference on each map that can be used to pull the historic map close to scale and provide reference to other points between the two maps.  Is there a way to link 2 images with "points" on each and transform one of the two base on the those links?

I have a script that allows you to enter the coordinates of 2 points in the two images; it will then move. stretch or shrink and rotate in one operation (thereby minimising interpolation artifacts) - see Align Layer Numerically here: http://programmer97.byethost10.com/GIMP.html

[skip671]

(05-23-2023, 04:11 PM)programmer_ceds Wrote:

(05-23-2023, 02:51 PM)skip671 Wrote: I have 2 images (maps).  One is a scale image from Google Maps.  The other is an historic map that is not to scale.  There are certain points of reference on each map that can be used to pull the historic map close to scale and provide reference to other points between the two maps.  Is there a way to link 2 images with "points" on each and transform one of the two base on the those links?

I have a script that allows you to enter the coordinates of 2 points in the two images; it will then move. stretch or shrink and rotate in one operation (thereby minimising interpolation artifacts) - see Align Layer Numerically here: http://programmer97.byethost10.com/GIMP.html

Thanks for the response.  Can the script be modified to allow more than 2 points?  As I try to reconcile maps, I will be trying to use as many points as possible (known street intersections, hill peaks, river/creek bends, etc).  The more points that are known and fixed should help to provide better context for the dissimilar/changed objects.

[Ofnuts]

The problem with maps is that even if they are accurate (so, ruling out "historic" maps...) they may use totally different projections so the problem is not a simple matter of scale and rotation.

You could investigate using panorama or focus apps, they always have some functionality to match points between two shots.

[denzjos]

You can try this: https://www.gimp-forum.net/Thread-Align-...ht=denzjos
But as Ofnuts mentioned, there could be some distortion other than just misalignment. Hugin is an option : https://hugin.sourceforge.io