gen_std_bandpassgen_std_bandpassGenStdBandpassGenStdBandpass (Operator)
Name
gen_std_bandpassgen_std_bandpassGenStdBandpassGenStdBandpass — Generate a bandpass filter with Gaussian or sinusoidal shape.
Signature
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)
void HImage::GenStdBandpass(double Frequency, double Sigma, const wchar_t* Type, const wchar_t* Norm, const wchar_t* Mode, Hlong Width, Hlong Height)
(Windows only)
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
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Processed without parallelization.
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