# What is spatial correlation and spatial convolution?

What does the term spatial correlation and spatial convolution mean with respect to digital image processing ?

• While Spatial Convolution is certainly an operation done over signals defined in Spatial Indices Spatial Correlation can be interpreted either as an operation (Correlation, as a flipped convolution) or a property, namely signal which is values have spatial correlation one with each other. What do you mean? Only as operations? – Royi Nov 18 '19 at 7:42

These terms exist mainly for historical reasons. In signal processing the signal is a one-dimensional function of time. So people talk about the time domain vs. the frequency domain. On the other hand, in image processing you are looking at a 2D function of $x$ and $y$, and there is no notion of time. Instead your are talking about spatial frequencies. Hence, spatial correlation and spatial convolution.