HALCON 21.05.0.0 / HALCON Operator Reference / Filters / FFT
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gen_sin_bandpassgen_sin_bandpassGenSinBandpassGenSinBandpassgen_sin_bandpass (Operator)

Name

gen_sin_bandpassgen_sin_bandpassGenSinBandpassGenSinBandpassgen_sin_bandpass — Generate a bandpass filter with sinusoidal shape.

Signature

gen_sin_bandpass( : ImageFilter : Frequency, Norm, Mode, Width, Height : )

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

Herror T_gen_sin_bandpass(Hobject* ImageFilter, const Htuple Frequency, const Htuple Norm, const Htuple Mode, const Htuple Width, const Htuple Height)

void GenSinBandpass(HObject* ImageFilter, const HTuple& Frequency, const HTuple& Norm, const HTuple& Mode, const HTuple& Width, const HTuple& Height)

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

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

void HImage::GenSinBandpass(double Frequency, const wchar_t* Norm, const wchar_t* Mode, Hlong Width, Hlong Height)   (Windows only)

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

void HImage.GenSinBandpass(double frequency, string norm, string mode, int width, int height)

def gen_sin_bandpass(frequency: float, norm: str, mode: str, width: int, height: int) -> HObject

Description

gen_sin_bandpassgen_sin_bandpassGenSinBandpassGenSinBandpassGenSinBandpassgen_sin_bandpass generates a rotationally invariant bandpass filter with the response being a sinusoidal function in the frequency domain. The maximum of the sine is determined by FrequencyFrequencyFrequencyFrequencyfrequencyfrequency, which is given as a fraction of the maximum (horizontal and vertical) frequency that can be represented in an image of size WidthWidthWidthWidthwidthwidth x HeightHeightHeightHeightheightheight, i.e., FrequencyFrequencyFrequencyFrequencyfrequencyfrequency should lie between 0 and 1. 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_genericFftGenericFftGenericFftGenericfft_generic 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_genericFftGenericFftGenericFftGenericfft_generic is used, 'dc_edge'"dc_edge""dc_edge""dc_edge""dc_edge""dc_edge" can be used to gain efficiency. If fft_imagefft_imageFftImageFftImageFftImagefft_image and fft_image_invfft_image_invFftImageInvFftImageInvFftImageInvfft_image_inv 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_genericRftGenericRftGenericRftGenericrft_generic is used, ModeModeModeModemodemode = 'rft'"rft""rft""rft""rft""rft" must be used. The filter is always zero for the DC term, rises with the sine function up to FrequencyFrequencyFrequencyFrequencyfrequencyfrequency, and drops for higher frequencies accordingly. The range of the sine used is from 0 to . All other points are set to zero.

Execution Information

Parameters

ImageFilterImageFilterImageFilterImageFilterimageFilterimage_filter (output_object)  image → objectHImageHObjectHImageHobject * (real)

Bandpass filter as image in the frequency domain.

FrequencyFrequencyFrequencyFrequencyfrequencyfrequency (input_control)  real → HTuplefloatHTupleHtuple (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

NormNormNormNormnormnorm (input_control)  string → HTuplestrHTupleHtuple (string) (string) (HString) (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 → HTuplestrHTupleHtuple (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" "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 → HTupleintHTupleHtuple (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

HeightHeightHeightHeightheightheight (input_control)  integer → HTupleintHTupleHtuple (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_sin_bandpassgen_sin_bandpassGenSinBandpassGenSinBandpassGenSinBandpassgen_sin_bandpass returns TRUE if all parameters are correct. If necessary, an exception is raised.

Possible Predecessors

fft_imagefft_imageFftImageFftImageFftImagefft_image, fft_genericfft_genericFftGenericFftGenericFftGenericfft_generic, rft_genericrft_genericRftGenericRftGenericRftGenericrft_generic

Possible Successors

convol_fftconvol_fftConvolFftConvolFftConvolFftconvol_fft

Alternatives

gen_std_bandpassgen_std_bandpassGenStdBandpassGenStdBandpassGenStdBandpassgen_std_bandpass

See also

fft_image_invfft_image_invFftImageInvFftImageInvFftImageInvfft_image_inv, gen_gauss_filtergen_gauss_filterGenGaussFilterGenGaussFilterGenGaussFiltergen_gauss_filter, gen_mean_filtergen_mean_filterGenMeanFilterGenMeanFilterGenMeanFiltergen_mean_filter, gen_derivative_filtergen_derivative_filterGenDerivativeFilterGenDerivativeFilterGenDerivativeFiltergen_derivative_filter, gen_bandpassgen_bandpassGenBandpassGenBandpassGenBandpassgen_bandpass, gen_bandfiltergen_bandfilterGenBandfilterGenBandfilterGenBandfiltergen_bandfilter, gen_highpassgen_highpassGenHighpassGenHighpassGenHighpassgen_highpass, gen_lowpassgen_lowpassGenLowpassGenLowpassGenLowpassgen_lowpass

Module

Foundation

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HALCON Operator Reference 21.05.0.0 Copyright © 1996-2021 MVTec Software GmbH
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