LocalMean must have size(V,1)^2 elements for your reshape to work. As the error message tells you, it hasn't. Since we have no idea what V is and thus how LocalMean is related to it, we can't tell you how to fix it.
Clearly, your code is not behaving the way you expect so you should check what it actually does by using the debugger. Step through your code line by line, see where it behaves differently frm what you expected and fix that.