If I threw a particular vector at every possible location in this image, what fraction of them will land both on white pixels.
I have a paper with 2 holes in it seperated by a particular vector. If I put this paper on a random location on top of the image, what is the probability that I will see a white pixel on both holes, given both holes reside within the image.
Normally, the location of each pixel in the image is described by a vector from the x axis, and a vector from the y axis. If I instead describe each white point, by vectors from every other white point in the image, how many times would I observe a particular vector (normalized by the number of points/vectors).