How to find the centroids and the angle between each of them?

Hi i found the centroids of the each white regions using regionprops. How can i find the distance and angle between each centroids and mark the points which are almost in straight line?

Answer 1

[Roger Stafford]

Once you know the centroids as x-y coordinates, it is easy to find their distances and angles. Suppose A = [x1,y1], B = [x2,y2], and C = [x3.y3] are three centroid positions.

For example, the distance between A and B is:

distAB = sqrt((x2-x1)^2+(y2-y1)^2);

and the interior angle in triangle ABC at centroid B is:

angB = atan2(abs((x1-x2)*(y3-y2)-(x3-x2)*(y1-y2)),...
                 (x1-x2)*(x3-x2)+(y1-y2)*(y3-y2));

[Alina tom]

Sir can you guide me how I fuse/ combine two images . one image is 2d having dimensions 512x271 and other image is 3d having dimensions 512x271x512. I want to combine them to make one image . the output image have size 512x271x512