Operator Reference

HALCON Operator Reference / Filters / Edges

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ClassesClasses | | Operators

laplace_of_gausslaplace_of_gaussLaplaceOfGaussLaplaceOfGausslaplace_of_gauss (Operator)

laplace_of_gausslaplace_of_gaussLaplaceOfGaussLaplaceOfGausslaplace_of_gauss — LoG-Operator (Laplace of Gaussian).

Signature

laplace_of_gauss(Image : ImageLaplace : Sigma : )

Herror laplace_of_gauss(const Hobject Image, Hobject* ImageLaplace, double Sigma)

Herror T_laplace_of_gauss(const Hobject Image, Hobject* ImageLaplace, const Htuple Sigma)

void LaplaceOfGauss(const HObject& Image, HObject* ImageLaplace, const HTuple& Sigma)

HImage HImage::LaplaceOfGauss(const HTuple& Sigma) const

HImage HImage::LaplaceOfGauss(double Sigma) const

static void HOperatorSet.LaplaceOfGauss(HObject image, out HObject imageLaplace, HTuple sigma)

HImage HImage.LaplaceOfGauss(HTuple sigma)

HImage HImage.LaplaceOfGauss(double sigma)

def laplace_of_gauss(image: HObject, sigma: Union[float, int]) -> HObject

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) → objectHImageHObjectHObjectHobject (byte / int1 / int2 / uint2 / int4 / real)

Input image.

ImageLaplaceImageLaplaceImageLaplaceimageLaplaceimage_laplace (output_object)  (multichannel-)image(-array) → objectHImageHObjectHObjectHobject * (int2)

Laplace filtered image.

SigmaSigmaSigmasigmasigma (input_control)  number → HTupleUnion[float, int]HTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

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

See also

derivate_gaussderivate_gaussDerivateGaussDerivateGaussderivate_gauss

Module

Foundation

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ClassesClasses | | Operators