Kernel "FreiChen" of size 3x3+1+1 with values from -1 to 1
Forming a output range from -2.41421 to 2.41421 (Zero-Summing)
 0:  0.707107         0 -0.707107
 1:         1         0        -1
 2:  0.707107         0 -0.707107