SRHNCalcResidual_PSF3x3, SRHNCalcResidual_PSF2x2

Syntax

Parameters

pHighRes

Pointer to high-resolution image.

highResStep

Distance in bytes between starts of consecutive lines in the pHighRes image.

pLowRes

Pointer to the array of pixel values from low-resolution images.

pOffset

Pointer to the array of offsets of 3x3 or 2x2 areas in the high-resolution image.

pCoeff

Pointer to the array of indexes of the coefficients in the input PSF table.

pRes

Pointer to the output array containing the calculated residuals.

len

Number of elements in the arrays pLowRes, pOffset, pCoeff and pRes.

pPSF

Pointer to the initialized table for 3x3 or 2x2 PSF.

Description

The functions ippiSRHNCalcResidual_PSF3x3 and ippiSRHNCalcResidual_PSF2x2 are declared in the ippcv.h file.

These functions computes residuals pRes for the likelihood part of the target function C (g) or its gradient ∇C(g). The calculated values are used as the arguments of the robust error functions or their derivatives. The following pseudocode shows how the calculation is performed.

for( int i = 0; i < len; i++ ) {
		const Ipp32f* ptr = hiRes + ofs[i];
		const Ipp32f* c = psf->cTab[coeff[i]];
		Ipp32f sum = 0;
		for( int dy = 0; dy < K; dy++ )
			for( int dx = 0; dx < K; dx++ )
				sum += c[dy*K+dx]*ptr[dy*hiResStep + dx];
		residual[i] = sum - lowRes[i];
}

Here K=3 for the 3x3 PSF, and K=2 for the 2x2 PSF.

The results stored in the pRes then can be passed to the robust error functions: ippsCauchy, ippsCauchyD, and ippsCauchyDD2 (see section "Arithmetic Functions" in the “Intel IPP Reference Manual” vol.1).

Return Values