ImageGear for C and C++ on Windows v19.1 - Updated
IG_FIP_restore_wiener
API Reference Guide > FreqIP Component API Reference > FreqIP Component Functions Reference > Filter Functions > IG_FIP_restore_wiener

This function performs image restoration using Wiener filtering in the frequency domain.

Declaration:

 
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AT_ERRCOUNT ACCUAPI IG_FIP_restore_wiener(
        HIGEAR hIGear, 
        const LPAT_RECT lpRect,
        LPAT_DOUBLE lpPSFVector, 
        const AT_INT nPSFSize, 
        const AT_DOUBLE dWienerConstant
);

Arguments:

Name Type Description
hIGear HIGEAR Handle of the input image, also pass out the restored 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.
lpPSFVector LPAT_DOUBLE Pointer to the vector which represents the Point Spread Function (PSF) in spatial domain, also called Degradation Function.
nPSFSize const AT_INT Size of PSF passed in lpPSFVector.
dWienerConstant const AT_DOUBLE The constant for Wiener Filtering.

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 */
AT_DOUBLE psfVector[11];
...
IG_FIP_restore_wiener(hIGear, NULL, psfVector, 11, 0.005);
...

Remarks:

This filter is also commonly referred to as the minimum mean square error filter or the least square error filter.

Generally speaking, Wiener filtering can produce better results than inverse filtering.