3 Image Enhan 3.5.1 Smoothing linear filtering >Two forms:uniform weights and un-uniform weights 1)uniformR=∑2g-g∑2,2》un-uniform R=∑w= Inversely proportional to distance 1 2 1 2 16 1 1 23 Image Enhancement 1 1 1 1 1 1 1 1 1 Two forms: uniform weights and un-uniform weights 1 2 1 2 4 2 1 2 1 1 16  9 9 1 1 1 1 9 9 i i i i R z z       9 1 i i i R w z  1)uniform 2)un-uniform   Inversely proportional to distance 1 9  3.5.1 Smoothing linear filtering