laplace_of_gausslaplace_of_gaussLaplaceOfGaussLaplaceOfGausslaplace_of_gauss (Operator)

Name

laplace_of_gausslaplace_of_gaussLaplaceOfGaussLaplaceOfGausslaplace_of_gauss — LoG-Operator (Laplace of Gaussian).

Signature

laplace_of_gauss(Image : ImageLaplace : Sigma : )

Description

laplace_of_gausslaplace_of_gaussLaplaceOfGaussLaplaceOfGausslaplace_of_gauss calculates the Laplace-of-Gaussian operator, i.e., the Laplace operator on a Gaussian smoothed image, for arbitrary smoothing parameters SigmaSigmaSigmasigmasigma. The Laplace operator is given by: The derivatives in laplace_of_gausslaplace_of_gaussLaplaceOfGaussLaplaceOfGausslaplace_of_gauss are calculated by appropriate derivatives of the Gaussian, resulting in the following formula for the convolution mask:

Attention

Note that filter operators may return may return unexpected results if an image with a reduced domain is used as input. Please refer to the chapter Filters.

Execution Information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Automatically parallelized on tuple level.
Automatically parallelized on channel level.
Automatically parallelized on domain level.

Parameters

ImageImageImageimageimage (input_object) (multichannel-)image(-array) → object (byte / int1 / int2 / uint2 / int4 / real)

Input image.

ImageLaplaceImageLaplaceImageLaplaceimageLaplaceimage_laplace (output_object) (multichannel-)image(-array) → object (int2)

Laplace filtered image.

SigmaSigmaSigmasigmasigma (input_control) number → (real / integer)

Smoothing parameter of the Gaussian.

Default: 2.0

Suggested values: 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 7.0

Value range: 0.01 ≤ Sigma Sigma Sigma sigma sigma ≤ 25.0

Minimum increment: 0.01

Recommended increment: 0.1

Example (C)

read_image(&Image,"mreut");
laplace_of_gauss(Image,&Laplace,2.0);
zero_crossing(Laplace,&ZeroCrossings);

Possible Successors

zero_crossingzero_crossingZeroCrossingZeroCrossingzero_crossing, dual_thresholddual_thresholdDualThresholdDualThresholddual_threshold

Alternatives

laplacelaplaceLaplaceLaplacelaplace, diff_of_gaussdiff_of_gaussDiffOfGaussDiffOfGaussdiff_of_gauss, derivate_gaussderivate_gaussDerivateGaussDerivateGaussderivate_gauss

Module

Foundation

Operators