RGB图像灰度化

#include "opencv2/highgui.hpp"
#include "opencv2/imgproc.hpp"
#include <iostream>
using namespace cv;
using namespace std;

const int BGR_TO_GRAY_AVERAGING_SHIFT = 8;
const int BGR_TO_GRAY_ROUND_TERM = 1 << (BGR_TO_GRAY_AVERAGING_SHIFT - 1);
const int BLUE_TO_GRAY_WEIGHT = int(0.114*(1 << BGR_TO_GRAY_AVERAGING_SHIFT) + 0.5);
const int GREEN_TO_GRAY_WEIGHT = int(0.587*(1 << BGR_TO_GRAY_AVERAGING_SHIFT) + 0.5);
const int RED_TO_GRAY_WEIGHT = 255 - BLUE_TO_GRAY_WEIGHT - GREEN_TO_GRAY_WEIGHT;
void RGB2Y(unsigned char *Src, unsigned char *Dest, int Width, int Height, int Stride);

inline const unsigned char BgrToGray(int blue, int green, int red)
{
	return (BLUE_TO_GRAY_WEIGHT*blue + GREEN_TO_GRAY_WEIGHT * green +
		RED_TO_GRAY_WEIGHT * red ) >> BGR_TO_GRAY_AVERAGING_SHIFT;
}


void BgraToGray(const unsigned char * bgra, size_t width, size_t height, size_t bgraStride, unsigned char * gray, size_t grayStride)
{
	for (size_t row = 0; row < height; ++row)
	{
		const unsigned char * pBgra = bgra + row*bgraStride;
		unsigned char * pGray = gray + row*grayStride;
		for (const uint8_t *pGrayEnd = pGray + width; pGray < pGrayEnd; pGray += 1, pBgra += 3)
		{
				*pGray = BgrToGray(pBgra[0], pBgra[1], pBgra[2]);			
		}
	}
}

int main(int argc, char** argv)
{
	Mat src = imread("C:/Users/lvmeng/Desktop/Image/hua.jpg", 1);

	int Height = src.rows;
	int Width = src.cols;
	unsigned char *Src = src.data;
	unsigned char *Dest = new unsigned char[Height * Width];

	int64 st = cvGetTickCount();

	BgraToGray(Src, Width, Height, Width * 3, Dest, Width);

	double duration = 1000*((cv::getTickCount() - st) / cv::getTickFrequency() ) ;
	printf("%.5f\n", duration);

	Mat dst(Height, Width, CV_8UC1, Dest);

	imshow("aaaaaa", dst);
	cvWaitKey(0);

	system("pause");
	return 0;
}