Image shrinking

sum these pixels

1/a

n/a

n-th pixel

2l=support size of h(x)

Can replace the box

by other

functions (filters)

that result in better

images.

The formula is the

same:

We have to sum only over pixels for which

h(ai - n) is not zero. If h(x) is zero outside [-l,l],

The range for i is determined from