多分辨率融合

class LaplacianBlending {
private:
	Mat_<Vec3f> left;  // 左图
	Mat_<Vec3f> right; // 右图
	Mat_<float> blendMask; // 融合线掩码
	vector<Mat_<Vec3f> > leftLapPyr,rightLapPyr,resultLapPyr; //拉普拉斯金字塔
	Mat leftHighestLevel, rightHighestLevel, resultHighestLevel; //金字塔高度
	vector<Mat_<Vec3f> > maskGaussianPyramid; //掩码的高斯金字塔
	int levels;
	void buildPyramids() { ..
		buildLaplacianPyramid(left, leftLapPyr, leftHighestLevel);
		buildLaplacianPyramid(right,rightLapPyr,rightHighestLevel);
		buildGaussianPyramid();
	}
	void buildGaussianPyramid() {
		assert(leftLapPyr.size()>0);
		maskGaussianPyramid.clear();
		Mat currentImg;
		cvtColor(blendMask, currentImg, CV_GRAY2BGR);//store color img of blend mask 			into maskGaussianPyramid
		maskGaussianPyramid.push_back(currentImg); //0-level
		currentImg = blendMask;
		for (int l=1; l<levels+1; l++) {
			Mat _down;
			if (leftLapPyr.size() > l)
				pyrDown(currentImg, _down, leftLapPyr[l].size());
			else
				pyrDown(currentImg, _down, leftHighestLevel.size()); //lowest level
			Mat down;
			cvtColor(_down, down, CV_GRAY2BGR);
			maskGaussianPyramid.push_back(down);//add color blend mask into mask Pyramid
			currentImg = _down;
		}
	}
	void buildLaplacianPyramid(const Mat& img, vector<Mat_<Vec3f> >& lapPyr, Mat& HighestLevel) {
		lapPyr.clear();
		Mat currentImg = img;
		for (int l=0; l<levels; l++) {
			Mat down,up;
			pyrDown(currentImg, down);
			pyrUp(down, up,currentImg.size());
			Mat lap = currentImg - up;
			lapPyr.push_back(lap);
			currentImg = down;
		}
		currentImg.copyTo(HighestLevel);
	}
    
	Mat_<Vec3f> reconstructImgFromLapPyramid() {
	//将左右laplacian图像拼成的resultLapPyr金字塔中每一层
	//从上到下插值放大并相加，即得blend图像结果
		Mat currentImg = resultHighestLevel;
		for (int l=levels-1; l>=0; l--) {
			Mat up;
			pyrUp(currentImg, up, resultLapPyr[l].size());
			currentImg = up + resultLapPyr[l];
		}
		return currentImg;
	}
	void blendLapPyrs() {
//获得每层金字塔中直接用左右两图Laplacian变换拼成的图像resultLapPyr
		resultHighestLevel = leftHighestLevel.mul(maskGaussianPyramid.back()) +
		rightHighestLevel.mul(Scalar(1.0,1.0,1.0) - maskGaussianPyramid.back());
		for (int l=0; l<levels; l++) {
			Mat A = leftLapPyr[l].mul(maskGaussianPyramid[l]);
			Mat antiMask = Scalar(1.0,1.0,1.0) - maskGaussianPyramid[l];
			Mat B = rightLapPyr[l].mul(antiMask);
			Mat_<Vec3f> blendedLevel = A + B;
			resultLapPyr.push_back(blendedLevel);
	}
}
public:
	LaplacianBlending(const Mat_<Vec3f>& _left, const Mat_<Vec3f>& _right, const Mat_<float>& _blendMask, int _levels)://construct function, used in LaplacianBlending lb(l,r,m,4);
left(_left),right(_right),blendMask(_blendMask),levels(_levels)
	{
		assert(_left.size() == _right.size());
		assert(_left.size() == _blendMask.size());
		buildPyramids(); //construct Laplacian Pyramid and Gaussian Pyramid
		blendLapPyrs(); //blend left & right Pyramids into one Pyramid
	};
	
	Mat_<Vec3f> blend() {
			return reconstructImgFromLapPyramid();//reconstruct Image from Laplacian Pyramid
		}
	};
	
	Mat_<Vec3f> LaplacianBlend(const Mat_<Vec3f>& l, const Mat_<Vec3f>& r, const 	Mat_<float>& m) {
		LaplacianBlending lb(l,r,m,4);
		return lb.blend();
	}
int main() {
	Mat l8u = imread("left.png");
	Mat r8u = imread("right.png");
	imshow("left",l8u);
	imshow("right",r8u);
	Mat_<Vec3f> l; l8u.convertTo(l,CV_32F,1.0/255.0);//Vec3f表示有三个通道，即 l[row][column][depth]
	Mat_<Vec3f> r; r8u.convertTo(r,CV_32F,1.0/255.0);
	Mat_<float> m(l.rows,l.cols,0.0); //将m全部赋值为0
	m(Range::all(),Range(0,m.cols/2)) = 1.0; //取m全部行&[0,m.cols/2]列，赋值为1.0
	Mat_<Vec3f> blend = LaplacianBlend(l, r, m);
	imshow("blended",blend);
	waitKey(0);
	return 0;
}