How to transform given XY coordinates using 'lwm' tform?
Hi, I have a set of XY coordinates, how do we transform given XY coordinates using 'lwm' tform? ROI_Coordinates_XY=[1,2; 2,3; 4,5; 6,7; 1,0; 1,6]; %XY coordinates that need to be transformed img1=imread('img1'); img2=imread('img2'); cpselect(img1, img2) %selecting control points keyboard img1_coordinates=movingPoints; clear movingPoints %save control points img2_coordinates=fixedPoints;clear fixedPoints %save fixed points tform_LWM = fitgeotrans(img1_coordinates, img2_coordinates, 'lwm', 10); %calculate tform using 'lwm' %Tranform ROI_Coordinates_XY using the same tform_LWM. tform_ed_XY = Help_function (tform_LWM, ROI_Coordinates_XY); %I am looking for a function like transformPointsForward for tform_LWM.
John Michell answered .
2025-11-20
A forward version of the lwm transform is not provided because it is not guaranteed to be a 1-1 transformation, but perhaps it would be useful to you simply to do the inverse fit
tform_inv = fitgeotrans(img2_coordinates, img1_coordinates, 'lwm', 10);
and then apply transformPointsInverse.