一个计算reprojection error的小程序

double reprojectionErrorCalculation(IplImage *rgbImage, CvMat *objectPoints, CvMat *imagePoints, CvMat *calibrationMatrix, CvMat *rotationMatrix, CvMat *translationVector){
	   IplImage* img=cvCreateImage(cvSize(rgbImage->width,rgbImage->height),rgbImage->depth,rgbImage->nChannels);
	   cvCopy(rgbImage,img);
	   int numPoints=objectPoints->height;
	   CvMat* translationMatrix=cvCreateMat(3,numPoints,CV_32FC1);
	   for(int i=0;i<3;i++){
		   float* ptr=(float*)(translationMatrix->data.ptr+i*translationMatrix->step);
		   float* ptrTranslation=(float*)(translationVector->data.ptr+i*translationVector->step);
		   for(int j=0;j<numPoints;j++){
		       *(ptr+j)=*ptrTranslation;
		   }
	   }

	   CvMat* objectPointsTranspose=cvCreateMat(3,numPoints,CV_32FC1);
	   cvTranspose(objectPoints,objectPointsTranspose);
	   CvMat* imagePointsHomogeneous=cvCreateMat(3,numPoints,CV_32FC1);
	   cvMatMulAdd(rotationMatrix,objectPointsTranspose,translationMatrix,imagePointsHomogeneous);

	   cvMatMul(calibrationMatrix,imagePointsHomogeneous,imagePointsHomogeneous);

	   CvMat* imagePointsReproject=cvCreateMat(numPoints,2,CV_32FC1);
	   cvConvertPointsHomogeneous(imagePointsHomogeneous,imagePointsReproject);

	   CvMat* reprojectionErrorMatrix=cvCreateMat(numPoints,2,CV_32FC1);
	   cvSub(imagePoints,imagePointsReproject,reprojectionErrorMatrix);
	   cvPow(reprojectionErrorMatrix,reprojectionErrorMatrix,2.0);
	   CvScalar reprojectionError=cvSum(reprojectionErrorMatrix);
	   reprojectionError.val[0]=sqrt(reprojectionError.val[0]/numPoints);

	   printf("The reprojection error is:\t%lf\n",reprojectionError.val[0]);

	   for(int i=0;i<numPoints;i++){
		   float* ptrOriginal=(float*)(imagePoints->data.ptr+i*imagePoints->step);
		   float* ptrReproject=(float*)(imagePointsReproject->data.ptr+i*imagePointsReproject->step);
		   cvLine(img,cvPoint(*(ptrOriginal)-3.0,*(ptrOriginal+1)),cvPoint(*(ptrOriginal)+3.0,*(ptrOriginal+1)),CV_RGB(255.0,0.0,0.0));
		   cvLine(img,cvPoint(*(ptrOriginal),*(ptrOriginal+1)-3.0),cvPoint(*(ptrOriginal),*(ptrOriginal+1)+3.0),CV_RGB(255.0,0.0,0.0));
		   cvLine(img,cvPoint(*(ptrReproject)-3.0,*(ptrReproject+1)),cvPoint(*(ptrReproject)+3.0,*(ptrReproject+1)),CV_RGB(0.0,255.0,0.0));
		   cvLine(img,cvPoint(*(ptrReproject),*(ptrReproject+1)-3.0),cvPoint(*(ptrReproject),*(ptrReproject+1)+3.0),CV_RGB(0.0,255.0,0.0));
	   }

	   cvNamedWindow("reprojection error");
       cvShowImage("reprojection error",img);
	   while(1){
	         if(cvWaitKey(2)==27)
				 break;
	   }
	   cvDestroyWindow("reprojection error");
	   cvReleaseImage(&img);

	   cvReleaseMat(&translationMatrix);
	   cvReleaseMat(&objectPointsTranspose);
	   cvReleaseMat(&imagePointsHomogeneous);
	   cvReleaseMat(&imagePointsReproject);
	   cvReleaseMat(&reprojectionErrorMatrix);
       return reprojectionError.val[0];
}