/** 
* @file GenericImageTools.cpp
* @brief simple filter stuff
* @author Erik Rodner
* @date 07/30/2008

*/
#include <iostream>

#include "GenericImageTools.h"

template <class PixelValueDst, class PixelValueSrc>
void GenericImageTools::calcIntegralImage ( PixelValueDst *integralImage, const PixelValueSrc *image, int xsize, int ysize )
{
    integralImage[0] = image[0];

    int k = xsize;
    for ( int y = 1 ; y < ysize; y++, k+=xsize )
	integralImage[k] = (PixelValueDst)(integralImage[k-xsize] + image[k]);

    k = 1;
    for ( int x = 1 ; x < xsize; x++, k++ )
	integralImage[k] = (PixelValueDst)(integralImage[k-1] + image[k]);

    k = xsize + 1;
    for ( int y = 1 ; y < ysize ; y++,k++ )
	for ( int x = 1 ; x < xsize ; x++,k++ )
	{
	    integralImage[k] = (PixelValueDst)image[k];
	    integralImage[k] += integralImage[k-1]; 
	    integralImage[k] += integralImage[k - xsize];
	    integralImage[k] -= integralImage[k - xsize - 1];
	}
}

template <class PixelValueDst, class PixelValueSrc>
void GenericImageTools::nonMaximumSuppression ( PixelValueDst *dst, const PixelValueSrc *src,
    int xsize, int ysize, bool useEightConnectivity )
{
    long k = 0;
    for ( int y = 0 ; y < ysize ; y++ )
	for ( int x = 0 ; x < xsize ; x++,k++ )
	{
	    if ( x != 0 )
	    {
			if ( src[k-1] > src[k] ) { dst[k] = 0; continue; };
			if ( useEightConnectivity ) {
				if ( ( y != 0 ) && ( src[k-xsize-1] > src[k] ) ) { dst[k] = 0; continue; };
				if ( ( y != ysize-1 ) && ( src[k+xsize-1] > src[k] ) ) { dst[k] = 0; continue; };
			}
	    }

	    if ( x != xsize-1 ) 
	    {
			if ( src[k+1] > src[k] ) { dst[k] = 0; continue; };
			if ( useEightConnectivity ) {
				if ( ( y != 0 ) && ( src[k-xsize+1] > src[k] ) ) { dst[k] = 0; continue; };
				if ( ( y != ysize-1 ) && ( src[k+xsize+1] > src[k] ) ) { dst[k] = 0; continue; };
			}
	    }

	    // CHANGE THIS to dst <-> src !!

	    if ( y != 0 ) 
			if ( src[k-xsize] > src[k] ) { dst[k] = 0; continue; };
	    
	    if ( y != ysize-1 ) 
			if ( src[k+xsize] > src[k] ) { dst[k] = 0; continue; };

	    dst[k] = src[k];
	}

}