feConvolveMatrix
order="3"
kernelMatrix="0 0 0 
              0 1 0 
              0 0 0"
order="3"
kernelMatrix="-1  -1  -1
              -1   7  -1
              -1  -1  -1"
order="3"
kernelMatrix="-1 2 -1 
              -1 1 -1 
              -1 2 -1"
order="3"
kernelMatrix="-1 -1 -1 
               2  1  2 
              -1 -1 -1"
order="3"
kernelMatrix="1  -1   1
             -1  -1  -1
              1  -1   1"
order="3"
kernelMatrix="1   -1   1
             -1  -.1  -1
              1   -1   1"
order="5"
kernelMatrix="1  1   1  1  1
              1 -2  -2 -2  1
              1 -2 .01 -2  1
              1 -2  -2 -2  1
              1  1   1  1  1"