make ranges -10 10


std = 1   laplacian of gaussian equals graph it
(2-(x^2+y^2)/(1))*e^((-x^2-y^2)/(2*1))/(2*3.14159*(1))


std=2
(2-(x^2+y^2)/(4))*e^((-x^2-y^2)/(2*4))/(2*3.14159*(4))



Gaussian std=1

e^((-x^2-y^2)/(2*1))/(2*3.14159*(1*1))

std=1.4 discrete filter  n=9 related to Canny operator Below is Laplacian of a Gaussian

0,0,3,2,2,2,3,0,0
0,2,3,5,5,5,3,2,0
3,3,5,3,0,3,5,3,3
2,5,3,-12,-23,-12,3,5,2
2,5,0,-23,-40,-23,0,5,2
2,5,3,-12,-23,-12,3,5,2
3,3,5,3,0,3,5,3,3
0,2,3,5,5,5,3,2,0
0,0,3,2,2,2,3,0,0


Discrete Gaussian n=5 sigma =1— Do difference of gaussian

0.003765,0.015019,0.023792,0.015019,0.003765
0.015019,0.059912,0.094907,0.059912,0.015019
0.023792,0.094907,0.150342,0.094907,0.023792
0.015019,0.059912,0.094907,0.059912,0.015019
0.003765,0.015019,0.023792,0.015019,0.003765

Discrete Gaussian n=5 sigma=.5
0.000002,0.000212,0.000922,0.000212,0.000002
0.000212,0.024745,0.107391,0.024745,0.000212
0.000922,0.107391,0.466066,0.107391,0.000922
0.000212,0.024745,0.107391,0.024745,0.000212
0.000002,0.000212,0.000922,0.000212,0.000002

Discrete Gaussian n=9 sigma=1.4



0.000031,0.000172,0.000584,0.001217,0.001554,0.001217,0.000584,0.000172,0.000031
0.000172,0.000955,0.003247,0.006761,0.008634,0.006761,0.003247,0.000955,0.000172
0.000584,0.003247,0.011036,0.022985,0.02935,0.022985,0.011036,0.003247,0.000584
0.001217,0.006761,0.022985,0.047869,0.061126,0.047869,0.022985,0.006761,0.001217
0.001554,0.008634,0.02935,0.061126,0.078053,0.061126,0.02935,0.008634,0.001554
0.001217,0.006761,0.022985,0.047869,0.061126,0.047869,0.022985,0.006761,0.001217
0.000584,0.003247,0.011036,0.022985,0.02935,0.022985,0.011036,0.003247,0.000584
0.000172,0.000955,0.003247,0.006761,0.008634,0.006761,0.003247,0.000955,0.000172
0.000031,0.000172,0.000584,0.001217,0.001554,0.001217,0.000584,0.000172,0.000031