HALCON Reference Manual 10.0.2
Table of Contents / Filters / FFT ClassesClassesClasses | | | Operators

gen_gauss_filtergen_gauss_filtergen_gauss_filterGenGaussFilterGenGaussFilter (Operator)

Name

gen_gauss_filtergen_gauss_filtergen_gauss_filterGenGaussFilterGenGaussFilter — Generate a Gaussian filter in the frequency domain.

Signature

gen_gauss_filter( : ImageGauss : Sigma1, Sigma2, Phi, Norm, Mode, Width, Height : )

Herror gen_gauss_filter(Hobject* ImageGauss, double Sigma1, double Sigma2, double Phi, const char* Norm, const char* Mode, const Hlong Width, const Hlong Height)

Herror T_gen_gauss_filter(Hobject* ImageGauss, const Htuple Sigma1, const Htuple Sigma2, const Htuple Phi, const Htuple Norm, const Htuple Mode, const Htuple Width, const Htuple Height)

Herror gen_gauss_filter(Hobject* ImageGauss, const HTuple& Sigma1, const HTuple& Sigma2, const HTuple& Phi, const HTuple& Norm, const HTuple& Mode, const HTuple& Width, const HTuple& Height)

HImage HImage::GenGaussFilter(const HTuple& Sigma1, const HTuple& Sigma2, const HTuple& Phi, const HTuple& Norm, const HTuple& Mode, const HTuple& Width, const HTuple& Height)

void HOperatorSetX.GenGaussFilter(
[out] IHUntypedObjectX** ImageGauss, [in] VARIANT Sigma1, [in] VARIANT Sigma2, [in] VARIANT Phi, [in] VARIANT Norm, [in] VARIANT Mode, [in] VARIANT Width, [in] VARIANT Height)

void HImageX.GenGaussFilter(
[in] double Sigma1, [in] double Sigma2, [in] double Phi, [in] BSTR Norm, [in] BSTR Mode, [in] Hlong Width, [in] Hlong Height)

static void HOperatorSet.GenGaussFilter(out HObject imageGauss, HTuple sigma1, HTuple sigma2, HTuple phi, HTuple norm, HTuple mode, HTuple width, HTuple height)

void HImage.GenGaussFilter(double sigma1, double sigma2, double phi, string norm, string mode, int width, int height)

Description

gen_gauss_filtergen_gauss_filtergen_gauss_filterGenGaussFilterGenGaussFilter generates a (possibly anisotropic) Gaussian filter in the frequency domain. The standard deviations (i.e., the amount of smoothing) of the Gaussian in the spatial domain are determined by Sigma1Sigma1Sigma1Sigma1sigma1 and Sigma2Sigma2Sigma2Sigma2sigma2. Sigma1Sigma1Sigma1Sigma1sigma1 is the standard deviation in the principal direction of the filter in the spatial domain determined by the angle PhiPhiPhiPhiphi. To achieve a maximum overall efficiency of the filtering operation, the parameter NormNormNormNormnorm can be used to specify the normalization factor of the filter. If fft_genericfft_genericfft_genericFftGenericFftGeneric and NormNormNormNormnorm = 'n'"n""n""n""n" is used the normalization in the FFT can be avoided. ModeModeModeModemode can be used to determine where the DC term of the filter lies or whether the filter should be used in the real-valued FFT. If fft_genericfft_genericfft_genericFftGenericFftGeneric is used, 'dc_edge'"dc_edge""dc_edge""dc_edge""dc_edge" can be used to gain efficiency. If fft_imagefft_imagefft_imageFftImageFftImage and fft_image_invfft_image_invfft_image_invFftImageInvFftImageInv are used for filtering, NormNormNormNormnorm = 'none'"none""none""none""none" and ModeModeModeModemode = 'dc_center'"dc_center""dc_center""dc_center""dc_center" must be used. If rft_genericrft_genericrft_genericRftGenericRftGeneric is used, ModeModeModeModemode = 'rft'"rft""rft""rft""rft" must be used.

Parallelization

Parameters

ImageGaussImageGaussImageGaussImageGaussimageGauss (output_object)  image → objectHImageHImageHImageXHobject * (real)

Gaussian filter as image in the frequency domain.

Sigma1Sigma1Sigma1Sigma1sigma1 (input_control)  real → HTupleHTupleVARIANTHtuple (real) (double) (double) (double) (double)

Standard deviation of the Gaussian in the principal direction of the filter in the spatial domain.

Default value: 1.0

Suggested values: 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.5, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0

Restriction: Sigma1 >= 0

Sigma2Sigma2Sigma2Sigma2sigma2 (input_control)  real → HTupleHTupleVARIANTHtuple (real) (double) (double) (double) (double)

Standard deviation of the Gaussian perpendicular to the principal direction of the filter in the spatial domain.

Default value: 1.0

Suggested values: 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.5, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0

Restriction: Sigma2 >= 0

PhiPhiPhiPhiphi (input_control)  angle.rad → HTupleHTupleVARIANTHtuple (real) (double) (double) (double) (double)

Principal direction of the filter in the spatial domain.

Default value: 0.0

Suggested values: 0.0, 0.523599, 0.785398, 1.047198, 1.570796, 2.094395, 2.356194, 2.617994, 3.141593

NormNormNormNormnorm (input_control)  string → HTupleHTupleVARIANTHtuple (string) (string) (char*) (BSTR) (char*)

Normalizing factor of the filter.

Default value: 'none' "none" "none" "none" "none"

List of values: 'none'"none""none""none""none", 'n'"n""n""n""n"

ModeModeModeModemode (input_control)  string → HTupleHTupleVARIANTHtuple (string) (string) (char*) (BSTR) (char*)

Location of the DC term in the frequency domain.

Default value: 'dc_center' "dc_center" "dc_center" "dc_center" "dc_center"

List of values: 'dc_center'"dc_center""dc_center""dc_center""dc_center", 'dc_edge'"dc_edge""dc_edge""dc_edge""dc_edge", 'rft'"rft""rft""rft""rft"

WidthWidthWidthWidthwidth (input_control)  integer → HTupleHTupleVARIANTHtuple (integer) (int / long) (Hlong) (Hlong) (Hlong)

Width of the image (filter).

Default value: 512

List of values: 128, 160, 192, 256, 320, 384, 512, 640, 768, 1024, 2048, 4096, 8192

HeightHeightHeightHeightheight (input_control)  integer → HTupleHTupleVARIANTHtuple (integer) (int / long) (Hlong) (Hlong) (Hlong)

Height of the image (filter).

Default value: 512

List of values: 120, 128, 144, 240, 256, 288, 480, 512, 576, 1024, 2048, 4096, 8192

Example (HDevelop)

* Generate a smoothed derivative filter.
gen_gauss_filter (ImageGauss, Sigma, Sigma, 0, 'n', 'dc_edge', 512, 512)
convert_image_type (ImageGauss, ImageGaussComplex, 'complex')
gen_derivative_filter (ImageDerivX, 'x', 1, 'none', 'dc_edge', 512, 512)
mult_image (ImageGaussComplex, ImageDerivX, ImageDerivXGauss, 1, 0)
* Filter an image with the smoothed derivative filter.
fft_generic (Image, ImageFFT, 'to_freq', -1, 'none', 'dc_edge', 'complex')
convol_fft (ImageFFT, ImageDerivXGauss, Filtered)
fft_generic (Filtered, ImageX, 'from_freq', 1, 'none', 'dc_edge', 'real')

Result

gen_gauss_filtergen_gauss_filtergen_gauss_filterGenGaussFilterGenGaussFilter returns 2 (H_MSG_TRUE) if all parameters are correct. If necessary, an exception is raised.

Possible Predecessors

fft_imagefft_imagefft_imageFftImageFftImage, fft_genericfft_genericfft_genericFftGenericFftGeneric, rft_genericrft_genericrft_genericRftGenericRftGeneric

Possible Successors

convol_fftconvol_fftconvol_fftConvolFftConvolFft

See also

fft_image_invfft_image_invfft_image_invFftImageInvFftImageInv, gen_mean_filtergen_mean_filtergen_mean_filterGenMeanFilterGenMeanFilter, gen_derivative_filtergen_derivative_filtergen_derivative_filterGenDerivativeFilterGenDerivativeFilter, gen_lowpassgen_lowpassgen_lowpassGenLowpassGenLowpass, gen_bandpassgen_bandpassgen_bandpassGenBandpassGenBandpass, gen_bandfiltergen_bandfiltergen_bandfilterGenBandfilterGenBandfilter, gen_highpassgen_highpassgen_highpassGenHighpassGenHighpass

Module

Foundation

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HALCON Reference Manual 10.0.2 Copyright © 1996-2011 MVTec Software GmbH