ImageGear .NET v25.2 - Updated
ImageGear.Processing.Advanced Assembly / ImageGear.FreqIP Namespace / ImGearFrequencyProcessing Class / LowPassFilter Method
ImageGear.Core.ImGearRasterPage class object to be processed.
Brand of the filter to use. Constants are listed in ImGearFreqIPFilterBrands enumeration.
Cutoff frequency for the low-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
    LowPassFilter Method
    In This Topic
    Filters the input image using a low-pass filter, with the specified parameters.
    Syntax
    'Declaration
     
    Public Shared Sub LowPassFilter( _
       ByVal page As ImGearRasterPage, _
       ByVal filterBrand As ImGearFreqIPFilterBrands, _
       ByVal cutoffFrequency As Double, _
       ByVal filterOrder As Integer, _
       ByVal rippleFactor As Double _
    ) 
    'Usage
     
    Dim page As ImGearRasterPage
    Dim filterBrand As ImGearFreqIPFilterBrands
    Dim cutoffFrequency As Double
    Dim filterOrder As Integer
    Dim rippleFactor As Double
     
    ImGearFrequencyProcessing.LowPassFilter(page, filterBrand, cutoffFrequency, filterOrder, rippleFactor)
    public static void LowPassFilter( 
       ImGearRasterPage page,
       ImGearFreqIPFilterBrands filterBrand,
       double cutoffFrequency,
       int filterOrder,
       double rippleFactor
    )
    public: static void LowPassFilter( 
       ImGearRasterPage* page,
       ImGearFreqIPFilterBrands filterBrand,
       double cutoffFrequency,
       int filterOrder,
       double rippleFactor
    ) 
    public:
    static void LowPassFilter( 
       ImGearRasterPage^ page,
       ImGearFreqIPFilterBrands filterBrand,
       double cutoffFrequency,
       int filterOrder,
       double rippleFactor
    ) 

    Parameters

    page
    ImageGear.Core.ImGearRasterPage class object to be processed.
    filterBrand
    Brand of the filter to use. Constants are listed in ImGearFreqIPFilterBrands enumeration.
    cutoffFrequency
    Cutoff frequency for the low-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 low-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.

    Parameter cutoffFrequency specifies the cutoff frequency for the low-pass filter. This parameter 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.CanApplyLowPassFilter method can be called to check whether the operation can be performed or not.

    See Also