From analyzing Table 1, some interesting conclusions may be established. For instance, μ ̄ is smaller for less noisy images, but, more importantly, the values of μi,j are unevenly distributed within Ω. That is, by defining ΩE as the set embracing all regions with sharp gradients and similarly ΩS = Ω ΩE as the set for smooth regions, we see from Table 1