二维空间中两个三角形之间的映射关系

参考网址：http://blog.csdn.net/duanwuqing/article/details/5458286

代码实现方法一：

得到映射矩阵M

Mat ObtainM(vector <CvPoint> vOriginalPoint, vector <CvPoint> vMapPoint)
{
	Mat dstMapM;
	if (3 != vOriginalPoint.size())
	{
		return dstMapM;
	}

	CvMat*matOriginal = cvCreateMat(3, 3, CV_64FC1);
	cvZero(matOriginal);
	CvMat*matMap = cvCreateMat(3, 3, CV_64FC1);
	cvZero(matMap);

	for (int i = 0, iLen = vOriginalPoint.size(); i < iLen; ++i)
	{
		cvmSet(matOriginal, i, 0, vOriginalPoint[i].x);
		cvmSet(matOriginal, i, 1, vOriginalPoint[i].y);
		cvmSet(matOriginal, i, 2, 1);

		cvmSet(matMap, i, 0, vMapPoint[i].x);
		cvmSet(matMap, i, 1, vMapPoint[i].y);
		cvmSet(matMap, i, 2, 1);
	}
	

	CvMat *matOriginalInv;
	matOriginalInv = cvCreateMat(3, 3, CV_64FC1);

	double vX = cvInvert(matOriginal, matOriginalInv, CV_SVD);
	
	CvMat *matMapM;
	matMapM = cvCreateMat(3, 3, CV_64FC1);

	Mat mInv = Mat(matOriginalInv, true);
	Mat mMap = Mat(matMap, true);

	dstMapM = mInv * mMap;

	cvReleaseMat(&matOriginal);
	matOriginal = NULL;
	cvReleaseMat(&matMap);
	matMap = NULL;
	cvReleaseMat(&matOriginalInv);
	matOriginalInv = NULL;
	cvReleaseMat(&matMapM);
	matMapM = NULL;

	return dstMapM;
}

根据映射矩阵得到映射点位置
bool ObtainMPoint(cv::Mat mapM, CvPoint ptIn, CvPoint& ptOut)
{
	if (mapM.empty())
	{
		return false;
	}

	CvMat*matOriginal = cvCreateMat(1, 3, CV_64FC1);
	cvZero(matOriginal);

	cvmSet(matOriginal, 0, 0, ptIn.x);
	cvmSet(matOriginal, 0, 1, ptIn.y);
	cvmSet(matOriginal, 0, 2, 1);

	Mat mInv = Mat(matOriginal, true);

	Mat dstMapM = mInv * mapM;

	
	ptOut.x = dstMapM.at<double>(0, 0);
	ptOut.y = dstMapM.at<double>(0, 1);
	cvReleaseMat(&matOriginal);
	matOriginal = NULL;

	return true;
}

代码随便写写，专业勿喷！