IG_FIP_filter_bandpass

This function filters the input image using a band-pass filter, with the specified parameters.

Declaration:

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AT_ERRCOUNT ACCUAPI IG_FIP_filter_bandpass( HIGEAR hIGear, const LPAT_RECT lpRect, const AT_MODE nFilterBrand, const AT_DOUBLE dCutoffFreqLow, const AT_DOUBLE dCutoffFreqHigh, const AT_INT nFilterOrder, const AT_DOUBLE dRippleFactor );

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AT_ERRCOUNT ACCUAPI IG_FIP_filter_bandpass(
        HIGEAR hIGear, 
        const LPAT_RECT lpRect, 
        const AT_MODE nFilterBrand, 
        const AT_DOUBLE dCutoffFreqLow, 
        const AT_DOUBLE dCutoffFreqHigh,
        const AT_INT nFilterOrder, 
        const AT_DOUBLE dRippleFactor
);

Arguments:

Name	Type	Description
hIGear	HIGEAR	Handle of the input image, also pass out filtered image.
lpRect	const LPAT_RECT	Far pointer to an AT_RECT structure specifying the rectangular portion of the image on which to operate. If NULL, this operation will be performed on the entire image.
nFilterBrand	const AT_MODE	Brand of the filter to use. Constants IG_FREQIP_FILTER_BRAND_* are listed in file i_FreqIP.h.
dCutoffFreqLow	const AT_DOUBLE	Lower cutoff frequency for the band-pass filter.
dCutoffFreqHigh	const AT_DOUBLE	Higher cutoff frequency for the band-pass filter.
nFilterOrder	const AT_INT	Filter order to use, applicable to all except Ideal filter.
dRippleFactor	const AT_DOUBLE	A factor which determines the pass-band ripple for Chebyshev filters, with value between [0, 1].

Return Value:

Returns the number of ImageGear errors that occurred during this function call.

Supported Raster Image Formats:

Grayscale - 8 bpp.

Sample:

FreqIP

Example:

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HIGEAR hIGear; /* Handle of the input image */ ... IG_FIP_filter_bandpass(hIGear, NULL, IG_FREQIP_FILTER_BRAND_CHEBYSHEV_I , 0.3, 1, 0.5); ...

Remarks:

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

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