Suppose that I have an image with pixels and the following equation,
are the variables;
is the set of all the pixels;
is the set of all neighboring pixels of . For example, for an image with pixels,
is a weighting function where
Note: I just mentioned that it is an image to better explain the role of the set and the function .
Well, it's easy to show that "one" solution for that equation are the scalar multiples of the all-ones vector. I mean, is clearly a solution.
My question is: there's a way to proof that this is the "only" solution for the above equation?