Operators |
laplace_of_gauss — LoG-Operator (Laplace of Gaussian).
laplace_of_gauss(Image : ImageLaplace : Sigma : )
laplace_of_gauss calculates the Laplace-of-Gaussian operator, i.e., the Laplace operator on a Gaussian smoothed image, for arbitrary smoothing parameters Sigma. The Laplace operator is given by:
2 2 d d \/ g(x,y)) = --- g(x,y) + --- g(x,y) 2 2 dx dy
The derivatives in laplace_of_gauss are calculated by appropriate derivatives of the Gaussian, resulting in the following formula for the convolution mask:
/ 2 2 \ / 2 2 \ 1 | x + y | | x + y | \/ G (x,y) = ------- | ------ - 1 | exp | - ------ | s 4 | 2 | | 2 | 2 pi s \ 2 s / \ 2 s /
Input image.
Laplace filtered image.
Smoothing parameter of the Gaussian.
Default value: 2.0
Suggested values: 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 7.0
Typical range of values: 0.7 ≤ Sigma ≤ 5.0
Minimum increment: 0.01
Recommended increment: 0.1
Restriction: Sigma > 0.7 && Sigma <= 25.0
read_image(&Image,"mreut"); laplace_of_gauss(Image,&Laplace,2.0); zero_crossing(Laplace,&ZeroCrossings);
laplace, diff_of_gauss, derivate_gauss
Foundation
Operators |