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gen_std_bandpassgen_std_bandpassGenStdBandpassGenStdBandpass (Operator)

Name

gen_std_bandpassgen_std_bandpassGenStdBandpassGenStdBandpass — Generate a bandpass filter with Gaussian or sinusoidal shape.

Signature

gen_std_bandpass( : ImageFilter : Frequency, Sigma, Type, Norm, Mode, Width, Height : )

Herror gen_std_bandpass(Hobject* ImageFilter, double Frequency, double Sigma, const char* Type, const char* Norm, const char* Mode, const Hlong Width, const Hlong Height)

Herror T_gen_std_bandpass(Hobject* ImageFilter, const Htuple Frequency, const Htuple Sigma, const Htuple Type, const Htuple Norm, const Htuple Mode, const Htuple Width, const Htuple Height)

void GenStdBandpass(HObject* ImageFilter, const HTuple& Frequency, const HTuple& Sigma, const HTuple& Type, const HTuple& Norm, const HTuple& Mode, const HTuple& Width, const HTuple& Height)

void HImage::GenStdBandpass(double Frequency, double Sigma, const HString& Type, const HString& Norm, const HString& Mode, Hlong Width, Hlong Height)

void HImage::GenStdBandpass(double Frequency, double Sigma, const char* Type, const char* Norm, const char* Mode, Hlong Width, Hlong Height)

static void HOperatorSet.GenStdBandpass(out HObject imageFilter, HTuple frequency, HTuple sigma, HTuple type, HTuple norm, HTuple mode, HTuple width, HTuple height)

void HImage.GenStdBandpass(double frequency, double sigma, string type, string norm, string mode, int width, int height)

Description

gen_std_bandpassgen_std_bandpassGenStdBandpassGenStdBandpassGenStdBandpass generates a rotationally invariant bandpass filter with the response being determined by the parameters FrequencyFrequencyFrequencyFrequencyfrequency and SigmaSigmaSigmaSigmasigma: FrequencyFrequencyFrequencyFrequencyfrequency determines the location of the maximum response with respect to the DC term, while SigmaSigmaSigmaSigmasigma determines the width of the frequency band that passes the filter. FrequencyFrequencyFrequencyFrequencyfrequency and SigmaSigmaSigmaSigmasigma are specified as a fraction of the maximum (horizontal and vertical) frequency that can be represented in an image of size WidthWidthWidthWidthwidth x HeightHeightHeightHeightheight. FrequencyFrequencyFrequencyFrequencyfrequency should lie between 0 and 1. For TypeTypeTypeTypetype = 'gauss'"gauss""gauss""gauss""gauss", a Gaussian response is generated with SigmaSigmaSigmaSigmasigma being the standard deviation. For TypeTypeTypeTypetype = 'sin'"sin""sin""sin""sin", a sine function is generated with the maximum at FrequencyFrequencyFrequencyFrequencyfrequency and the extent SigmaSigmaSigmaSigmasigma. 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_genericFftGenericFftGenericFftGeneric 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_genericFftGenericFftGenericFftGeneric is used, 'dc_edge'"dc_edge""dc_edge""dc_edge""dc_edge" can be used to gain efficiency. If fft_imagefft_imageFftImageFftImageFftImage and fft_image_invfft_image_invFftImageInvFftImageInvFftImageInv 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_genericRftGenericRftGenericRftGeneric is used, ModeModeModeModemode = 'rft'"rft""rft""rft""rft" must be used.

Execution Information

Parameters

ImageFilterImageFilterImageFilterImageFilterimageFilter (output_object)  image objectHImageHImageHobject * (real)

Bandpass filter as image in the frequency domain.

FrequencyFrequencyFrequencyFrequencyfrequency (input_control)  real HTupleHTupleHtuple (real) (double) (double) (double)

Distance of the filter's maximum from the DC term.

Default value: 0.1

Suggested values: 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0

Restriction: Frequency >= 0

SigmaSigmaSigmaSigmasigma (input_control)  real HTupleHTupleHtuple (real) (double) (double) (double)

Bandwidth of the filter (standard deviation).

Default value: 0.01

Suggested values: 0.002, 0.005, 0.01, 0.02, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.7, 1.0

Restriction: Sigma >= 0

TypeTypeTypeTypetype (input_control)  string HTupleHTupleHtuple (string) (string) (HString) (char*)

Filter type.

Default value: 'sin' "sin" "sin" "sin" "sin"

List of values: 'gauss'"gauss""gauss""gauss""gauss", 'sin'"sin""sin""sin""sin"

NormNormNormNormnorm (input_control)  string HTupleHTupleHtuple (string) (string) (HString) (char*)

Normalizing factor of the filter.

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

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

ModeModeModeModemode (input_control)  string HTupleHTupleHtuple (string) (string) (HString) (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 HTupleHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Width of the image (filter).

Default value: 512

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

HeightHeightHeightHeightheight (input_control)  integer HTupleHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Height of the image (filter).

Default value: 512

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

Result

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

Possible Predecessors

fft_imagefft_imageFftImageFftImageFftImage, fft_genericfft_genericFftGenericFftGenericFftGeneric, rft_genericrft_genericRftGenericRftGenericRftGeneric

Possible Successors

convol_fftconvol_fftConvolFftConvolFftConvolFft

Alternatives

gen_sin_bandpassgen_sin_bandpassGenSinBandpassGenSinBandpassGenSinBandpass

See also

fft_image_invfft_image_invFftImageInvFftImageInvFftImageInv, gen_gauss_filtergen_gauss_filterGenGaussFilterGenGaussFilterGenGaussFilter, gen_mean_filtergen_mean_filterGenMeanFilterGenMeanFilterGenMeanFilter, gen_derivative_filtergen_derivative_filterGenDerivativeFilterGenDerivativeFilterGenDerivativeFilter, gen_bandpassgen_bandpassGenBandpassGenBandpassGenBandpass, gen_bandfiltergen_bandfilterGenBandfilterGenBandfilterGenBandfilter, gen_highpassgen_highpassGenHighpassGenHighpassGenHighpass, gen_lowpassgen_lowpassGenLowpassGenLowpassGenLowpass

Module

Foundation


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