ImageGear .NET v25.2 - Updated
ImageGear.Processing.Advanced Assembly / ImageGear.FreqIP Namespace / ImGearFrequencyProcessing Class / BandPassFilter Method
ImageGear.Core.ImGearRasterPage class object to be processed.
Brand of the filter to use. Constants are listed in the ImGearFreqIPFilterBrands enumeration.
Lower cutoff frequency for the band-pass filter.
Higher cutoff frequency for the band-pass filter.
Filter order to use, applicable to all except Ideal filter.
A factor which determines the pass-band ripple for Chebyshev filters, with value between [0, 1].




In This Topic
    BandPassFilter Method
    In This Topic
    Filters the input image using a band-pass filter, with the specified parameters.
    Syntax
    'Declaration
     
    Public Shared Sub BandPassFilter( _
       ByVal page As ImGearRasterPage, _
       ByVal filterBrand As ImGearFreqIPFilterBrands, _
       ByVal lowerCutoffFrequency As Double, _
       ByVal higherCutoffFrequency As Double, _
       ByVal filterOrder As Integer, _
       ByVal rippleFactor As Double _
    ) 
    'Usage
     
    Dim page As ImGearRasterPage
    Dim filterBrand As ImGearFreqIPFilterBrands
    Dim lowerCutoffFrequency As Double
    Dim higherCutoffFrequency As Double
    Dim filterOrder As Integer
    Dim rippleFactor As Double
     
    ImGearFrequencyProcessing.BandPassFilter(page, filterBrand, lowerCutoffFrequency, higherCutoffFrequency, filterOrder, rippleFactor)

    Parameters

    page
    ImageGear.Core.ImGearRasterPage class object to be processed.
    filterBrand
    Brand of the filter to use. Constants are listed in the ImGearFreqIPFilterBrands enumeration.
    lowerCutoffFrequency
    Lower cutoff frequency for the band-pass filter.
    higherCutoffFrequency
    Higher cutoff frequency for the band-pass filter.
    filterOrder
    Filter order to use, applicable to all except Ideal filter.
    rippleFactor
    A factor which determines the pass-band ripple for Chebyshev filters, with value between [0, 1].
    Remarks
    This method filters the input image using a band-pass filter, with the specified parameters.

    Parameter filterBrand specifies the brand of filter to use, with available brands being Ideal, Butterworth, Gaussian, Chebyshev I, and Chebyshev II.

    Parameters lowerCutoffFrequency and higherCutoffFrequency specify the lower and upper cutoff frequencies for the band-pass filter. The parameters should have value within the range of [0, 1], where 0 is DC and 1 is the Nyquist frequency.

    Before using this method, like other frequency processing methods, InitializeFFTW method must be called first to initialize the support for FFTW.

    Can be applied only to 8bit grayscale images with one channel.

    ImGearFrequencyProcessingVerifier.CanApplyBandPassFilter method can be called to check whether the operation can be performed or not.

    See Also