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gen_gauss_filtergen_gauss_filterGenGaussFiltergen_gauss_filterGenGaussFilterGenGaussFilter (Operator)

Name

gen_gauss_filtergen_gauss_filterGenGaussFiltergen_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 GenGaussFilter(HObject* ImageGauss, const HTuple& Sigma1, const HTuple& Sigma2, const HTuple& Phi, const HTuple& Norm, const HTuple& Mode, const HTuple& Width, const HTuple& Height)

void HImage::GenGaussFilter(double Sigma1, double Sigma2, double Phi, const HString& Norm, const HString& Mode, Hlong Width, Hlong Height)

void HImage::GenGaussFilter(double Sigma1, double Sigma2, double Phi, const char* Norm, const char* Mode, Hlong Width, Hlong 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_filterGenGaussFiltergen_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 Sigma1Sigma1Sigma1Sigma1Sigma1sigma1 and Sigma2Sigma2Sigma2Sigma2Sigma2sigma2. Sigma1Sigma1Sigma1Sigma1Sigma1sigma1 is the standard deviation in the principal direction of the filter in the spatial domain determined by the angle PhiPhiPhiPhiPhiphi. To achieve a maximum overall efficiency of the filtering operation, the parameter NormNormNormNormNormnorm can be used to specify the normalization factor of the filter. If fft_genericfft_genericFftGenericfft_genericFftGenericFftGeneric and NormNormNormNormNormnorm = 'n'"n""n""n""n""n" is used the normalization in the FFT can be avoided. ModeModeModeModeModemode 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_genericFftGenericfft_genericFftGenericFftGeneric is used, 'dc_edge'"dc_edge""dc_edge""dc_edge""dc_edge""dc_edge" can be used to gain efficiency. If fft_imagefft_imageFftImagefft_imageFftImageFftImage and fft_image_invfft_image_invFftImageInvfft_image_invFftImageInvFftImageInv are used for filtering, NormNormNormNormNormnorm = 'none'"none""none""none""none""none" and ModeModeModeModeModemode = 'dc_center'"dc_center""dc_center""dc_center""dc_center""dc_center" must be used. If rft_genericrft_genericRftGenericrft_genericRftGenericRftGeneric is used, ModeModeModeModeModemode = 'rft'"rft""rft""rft""rft""rft" must be used.

Parallelization

Parameters

ImageGaussImageGaussImageGaussImageGaussImageGaussimageGauss (output_object)  image objectHImageHImageHImageHImageXHobject * (real)

Gaussian filter as image in the frequency domain.

Sigma1Sigma1Sigma1Sigma1Sigma1sigma1 (input_control)  real HTupleHTupleHTupleVARIANTHtuple (real) (double) (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

Sigma2Sigma2Sigma2Sigma2Sigma2sigma2 (input_control)  real HTupleHTupleHTupleVARIANTHtuple (real) (double) (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

PhiPhiPhiPhiPhiphi (input_control)  angle.rad HTupleHTupleHTupleVARIANTHtuple (real) (double) (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

NormNormNormNormNormnorm (input_control)  string HTupleHTupleHTupleVARIANTHtuple (string) (string) (HString) (char*) (BSTR) (char*)

Normalizing factor of the filter.

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

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

ModeModeModeModeModemode (input_control)  string HTupleHTupleHTupleVARIANTHtuple (string) (string) (HString) (char*) (BSTR) (char*)

Location of the DC term in the frequency domain.

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

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

WidthWidthWidthWidthWidthwidth (input_control)  integer HTupleHTupleHTupleVARIANTHtuple (integer) (int / long) (Hlong) (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

HeightHeightHeightHeightHeightheight (input_control)  integer HTupleHTupleHTupleVARIANTHtuple (integer) (int / long) (Hlong) (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_filterGenGaussFiltergen_gauss_filterGenGaussFilterGenGaussFilter returns 2 (H_MSG_TRUE) if all parameters are correct. If necessary, an exception is raised.

Possible Predecessors

fft_imagefft_imageFftImagefft_imageFftImageFftImage, fft_genericfft_genericFftGenericfft_genericFftGenericFftGeneric, rft_genericrft_genericRftGenericrft_genericRftGenericRftGeneric

Possible Successors

convol_fftconvol_fftConvolFftconvol_fftConvolFftConvolFft

See also

fft_image_invfft_image_invFftImageInvfft_image_invFftImageInvFftImageInv, gen_mean_filtergen_mean_filterGenMeanFiltergen_mean_filterGenMeanFilterGenMeanFilter, gen_derivative_filtergen_derivative_filterGenDerivativeFiltergen_derivative_filterGenDerivativeFilterGenDerivativeFilter, gen_lowpassgen_lowpassGenLowpassgen_lowpassGenLowpassGenLowpass, gen_bandpassgen_bandpassGenBandpassgen_bandpassGenBandpassGenBandpass, gen_bandfiltergen_bandfilterGenBandfiltergen_bandfilterGenBandfilterGenBandfilter, gen_highpassgen_highpassGenHighpassgen_highpassGenHighpassGenHighpass

Module

Foundation


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