Question

i need to find the distance between the two points.I can find the distance between them manually by the pixel to cm converter in the image processing tool box. But i want a code which detects the point positions in the image and calculate the distance.
More accurately speaking the image contains only three points one mid and the other two approximately distanced equally from it…

Answer 1

There might be a better way then this, but I hacked something similar together last night.

Use bwboundaries to find the objects in the image (the contiguous regions in a black/white image).

The second returned matrix, L, is the same image but with the regions numbered. So for the first point, you want to isolate all the pixels related to it,

L2 = (L==1)

Now find the center of that region (for object 1).

x1 = (1:size(L2,2))*sum(L2,1)'/size(L2,2);

y1 = (1:size(L2,1))*sum(L2,2)/size(L2,1);

Repeat that for all the regions in your image. You should have the center of mass of each point. I think that should do it for you, but I haven’t tested it.