Operator Reference

HALCON Operator Reference / Filters / FFT
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gen_mean_filtergen_mean_filterGenMeanFilterGenMeanFiltergen_mean_filter (Operator)

gen_mean_filtergen_mean_filterGenMeanFilterGenMeanFiltergen_mean_filter — Generate a mean filter in the frequency domain.

Signature

gen_mean_filter( : ImageMean : MaskShape, Diameter1, Diameter2, Phi, Norm, Mode, Width, Height : )

Herror gen_mean_filter(Hobject* ImageMean, const char* MaskShape, double Diameter1, double Diameter2, double Phi, const char* Norm, const char* Mode, const Hlong Width, const Hlong Height)

Herror T_gen_mean_filter(Hobject* ImageMean, const Htuple MaskShape, const Htuple Diameter1, const Htuple Diameter2, const Htuple Phi, const Htuple Norm, const Htuple Mode, const Htuple Width, const Htuple Height)

void GenMeanFilter(HObject* ImageMean, const HTuple& MaskShape, const HTuple& Diameter1, const HTuple& Diameter2, const HTuple& Phi, const HTuple& Norm, const HTuple& Mode, const HTuple& Width, const HTuple& Height)

void HImage::GenMeanFilter(const HString& MaskShape, double Diameter1, double Diameter2, double Phi, const HString& Norm, const HString& Mode, Hlong Width, Hlong Height)

void HImage::GenMeanFilter(const char* MaskShape, double Diameter1, double Diameter2, double Phi, const char* Norm, const char* Mode, Hlong Width, Hlong Height)

void HImage::GenMeanFilter(const wchar_t* MaskShape, double Diameter1, double Diameter2, double Phi, const wchar_t* Norm, const wchar_t* Mode, Hlong Width, Hlong Height)   ( Windows only)

static void HOperatorSet.GenMeanFilter(out HObject imageMean, HTuple maskShape, HTuple diameter1, HTuple diameter2, HTuple phi, HTuple norm, HTuple mode, HTuple width, HTuple height)

void HImage.GenMeanFilter(string maskShape, double diameter1, double diameter2, double phi, string norm, string mode, int width, int height)

def gen_mean_filter(mask_shape: str, diameter_1: float, diameter_2: float, phi: float, norm: str, mode: str, width: int, height: int) -> HObject

Description

gen_mean_filtergen_mean_filterGenMeanFilterGenMeanFiltergen_mean_filter generates a mean filter in the frequency domain. The shape of the mean filter is determined by MaskShapeMaskShapeMaskShapemaskShapemask_shape. For MaskShapeMaskShapeMaskShapemaskShapemask_shape = 'rectangle'"rectangle""rectangle""rectangle""rectangle", a rectangular mean filter is generated. For MaskShapeMaskShapeMaskShapemaskShapemask_shape = 'ellipse'"ellipse""ellipse""ellipse""ellipse", an elliptical mean filter is generated. The diameters (i.e., the amount of smoothing) of the mean filter in the spatial domain are determined by Diameter1Diameter1Diameter1diameter1diameter_1 and Diameter2Diameter2Diameter2diameter2diameter_2. Diameter1Diameter1Diameter1diameter1diameter_1 is the diameter 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_genericFftGenericFftGenericfft_generic 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_genericFftGenericFftGenericfft_generic is used, 'dc_edge'"dc_edge""dc_edge""dc_edge""dc_edge" can be used to gain efficiency. If fft_imagefft_imageFftImageFftImagefft_image and fft_image_invfft_image_invFftImageInvFftImageInvfft_image_inv 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_genericRftGenericRftGenericrft_generic is used, ModeModeModemodemode = 'rft'"rft""rft""rft""rft" must be used.

Execution Information

  • Multithreading type: reentrant (runs in parallel with non-exclusive operators).
  • Multithreading scope: global (may be called from any thread).
  • Processed without parallelization.

Parameters

ImageMeanImageMeanImageMeanimageMeanimage_mean (output_object)  image → objectHImageHObjectHObjectHobject * (real)

Mean filter as image in the frequency domain.

MaskShapeMaskShapeMaskShapemaskShapemask_shape (input_control)  string → HTuplestrHTupleHtuple (string) (string) (HString) (char*)

Shape of the filter mask in the spatial domain.

Default: 'ellipse' "ellipse" "ellipse" "ellipse" "ellipse"

List of values: 'ellipse'"ellipse""ellipse""ellipse""ellipse", 'rectangle'"rectangle""rectangle""rectangle""rectangle"

Diameter1Diameter1Diameter1diameter1diameter_1 (input_control)  real → HTuplefloatHTupleHtuple (real) (double) (double) (double)

Diameter of the mean filter in the principal direction of the filter in the spatial domain.

Default: 11.0

Suggested values: 3.0, 5.0, 7.0, 9.0, 11.0, 15.0, 21.0, 31.0, 51.0

Restriction: Diameter1 > 0

Diameter2Diameter2Diameter2diameter2diameter_2 (input_control)  real → HTuplefloatHTupleHtuple (real) (double) (double) (double)

Diameter of the mean filter perpendicular to the principal direction of the filter in the spatial domain.

Default: 11.0

Suggested values: 3.0, 5.0, 7.0, 9.0, 11.0, 15.0, 21.0, 31.0, 51.0

Restriction: Diameter2 > 0

PhiPhiPhiphiphi (input_control)  angle.rad → HTuplefloatHTupleHtuple (real) (double) (double) (double)

Principal direction of the filter in the spatial domain.

Default: 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 → HTuplestrHTupleHtuple (string) (string) (HString) (char*)

Normalizing factor of the filter.

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

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

ModeModeModemodemode (input_control)  string → HTuplestrHTupleHtuple (string) (string) (HString) (char*)

Location of the DC term in the frequency domain.

Default: '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 → HTupleintHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Width of the image (filter).

Default: 512

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

HeightHeightHeightheightheight (input_control)  integer → HTupleintHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Height of the image (filter).

Default: 512

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

Example (HDevelop)

* Generate a circular mean filter.
gen_mean_filter (FilterMean, 'ellipse', 15, 15, 0, 'n', 'dc_edge', 512, 512)
* Filter an image with the circular mean filter.
fft_generic (Image, ImageFFT, 'to_freq', -1, 'none', 'dc_edge', 'complex')
convol_fft (ImageFFT, FilterMean, Filtered)
fft_generic (Filtered, ImageMean, 'from_freq', 1, 'none', 'dc_edge', 'real')

Result

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

Possible Predecessors

fft_imagefft_imageFftImageFftImagefft_image, fft_genericfft_genericFftGenericFftGenericfft_generic, rft_genericrft_genericRftGenericRftGenericrft_generic

Possible Successors

convol_fftconvol_fftConvolFftConvolFftconvol_fft

See also

fft_image_invfft_image_invFftImageInvFftImageInvfft_image_inv, gen_gauss_filtergen_gauss_filterGenGaussFilterGenGaussFiltergen_gauss_filter, gen_derivative_filtergen_derivative_filterGenDerivativeFilterGenDerivativeFiltergen_derivative_filter, gen_lowpassgen_lowpassGenLowpassGenLowpassgen_lowpass, gen_bandpassgen_bandpassGenBandpassGenBandpassgen_bandpass, gen_bandfiltergen_bandfilterGenBandfilterGenBandfiltergen_bandfilter, gen_highpassgen_highpassGenHighpassGenHighpassgen_highpass

Module

Foundation

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