double CameraCalibration::FundamentalMatrixQuality(vector<vector<Point2f> > LeftImagePoints, vector<vector<Point2f> > RightImagePoints, Mat LeftCameraMatrix, Mat RightCameraMatrix, Mat LeftDistCoeffs, Mat RightDistCoeffs, Mat F) { // CALIBRATION QUALITY CHECK // because the output fundamental matrix implicitly // includes all the output information, // we can check the quality of calibration using the // epipolar geometry constraint: m2^t*F*m1=0 double err = 0; int npoints = 0; vector<Vec3f> lines[2]; for(int i = 0; i < NumFrames; i++ ) { int npt = (int)LeftImagePoints[i].size(); Mat imgpt[2]; imgpt[0] = Mat(LeftImagePoints[i]); imgpt[1] = Mat(RightImagePoints[i]); undistortPoints(imgpt[0], imgpt[0], LeftCameraMatrix, LeftDistCoeffs, Mat(), LeftCameraMatrix); undistortPoints(imgpt[1], imgpt[1], RightCameraMatrix, RightDistCoeffs, Mat(), RightCameraMatrix); computeCorrespondEpilines(imgpt[0], 1, F, lines[0]); computeCorrespondEpilines(imgpt[1], 2, F, lines[1]); for(int j = 0; j < npt; j++ ) { double errij = fabs(LeftImagePoints[i][j].x*lines[1][j][0] + LeftImagePoints[i][j].y*lines[1][j][1] + lines[1][j][2]) + fabs(RightImagePoints[i][j].x*lines[0][j][0] + RightImagePoints[i][j].y*lines[0][j][1] + lines[0][j][2]); err += errij; } npoints += npt; } return err/npoints; }
void stereoCalibThread::stereoCalibration(const vector<string>& imagelist, int boardWidth, int boardHeight,float sqsize) { Size boardSize; boardSize.width=boardWidth; boardSize.height=boardHeight; if( imagelist.size() % 2 != 0 ) { cout << "Error: the image list contains odd (non-even) number of elements\n"; return; } const int maxScale = 2; // ARRAY AND VECTOR STORAGE: std::vector<std::vector<Point2f> > imagePoints[2]; std::vector<std::vector<Point3f> > objectPoints; Size imageSize; int i, j, k, nimages = (int)imagelist.size()/2; imagePoints[0].resize(nimages); imagePoints[1].resize(nimages); std::vector<string> goodImageList; for( i = j = 0; i < nimages; i++ ) { for( k = 0; k < 2; k++ ) { const string& filename = imagelist[i*2+k]; Mat img = cv::imread(filename, 0); if(img.empty()) break; if( imageSize == Size() ) imageSize = img.size(); else if( img.size() != imageSize ) { cout << "The image " << filename << " has the size different from the first image size. Skipping the pair\n"; break; } bool found = false; std::vector<Point2f>& corners = imagePoints[k][j]; for( int scale = 1; scale <= maxScale; scale++ ) { Mat timg; if( scale == 1 ) timg = img; else resize(img, timg, Size(), scale, scale); if(boardType == "CIRCLES_GRID") { found = findCirclesGridDefault(timg, boardSize, corners, CALIB_CB_SYMMETRIC_GRID | CALIB_CB_CLUSTERING); } else if(boardType == "ASYMMETRIC_CIRCLES_GRID") { found = findCirclesGridDefault(timg, boardSize, corners, CALIB_CB_ASYMMETRIC_GRID | CALIB_CB_CLUSTERING); } else { found = findChessboardCorners(timg, boardSize, corners, CV_CALIB_CB_ADAPTIVE_THRESH | CV_CALIB_CB_NORMALIZE_IMAGE); } if( found ) { if( scale > 1 ) { Mat cornersMat(corners); cornersMat *= 1./scale; } break; } } if( !found ) break; } if( k == 2 ) { goodImageList.push_back(imagelist[i*2]); goodImageList.push_back(imagelist[i*2+1]); j++; } } fprintf(stdout,"%i pairs have been successfully detected.\n",j); nimages = j; if( nimages < 2 ) { fprintf(stdout,"Error: too few pairs detected \n"); return; } imagePoints[0].resize(nimages); imagePoints[1].resize(nimages); objectPoints.resize(nimages); for( i = 0; i < nimages; i++ ) { for( j = 0; j < boardSize.height; j++ ) for( k = 0; k < boardSize.width; k++ ) objectPoints[i].push_back(Point3f(j*squareSize, k*squareSize, 0)); } fprintf(stdout,"Running stereo calibration ...\n"); Mat cameraMatrix[2], distCoeffs[2]; Mat E, F; if(this->Kleft.empty() || this->Kright.empty()) { double rms = stereoCalibrate(objectPoints, imagePoints[0], imagePoints[1], this->Kleft, this->DistL, this->Kright, this->DistR, imageSize, this->R, this->T, E, F, TermCriteria(CV_TERMCRIT_ITER+CV_TERMCRIT_EPS, 100, 1e-5), CV_CALIB_FIX_ASPECT_RATIO + CV_CALIB_ZERO_TANGENT_DIST + CV_CALIB_SAME_FOCAL_LENGTH + CV_CALIB_FIX_K3); fprintf(stdout,"done with RMS error= %f\n",rms); } else { double rms = stereoCalibrate(objectPoints, imagePoints[0], imagePoints[1], this->Kleft, this->DistL, this->Kright, this->DistR, imageSize, this->R, this->T, E, F, TermCriteria(CV_TERMCRIT_ITER+CV_TERMCRIT_EPS, 100, 1e-5),CV_CALIB_FIX_ASPECT_RATIO + CV_CALIB_FIX_INTRINSIC + CV_CALIB_FIX_K3); fprintf(stdout,"done with RMS error= %f\n",rms); } // CALIBRATION QUALITY CHECK cameraMatrix[0] = this->Kleft; cameraMatrix[1] = this->Kright; distCoeffs[0]=this->DistL; distCoeffs[1]=this->DistR; Mat R, T; T=this->T; R=this->R; double err = 0; int npoints = 0; std::vector<Vec3f> lines[2]; for( i = 0; i < nimages; i++ ) { int npt = (int)imagePoints[0][i].size(); Mat imgpt[2]; for( k = 0; k < 2; k++ ) { imgpt[k] = Mat(imagePoints[k][i]); undistortPoints(imgpt[k], imgpt[k], cameraMatrix[k], distCoeffs[k], Mat(), cameraMatrix[k]); computeCorrespondEpilines(imgpt[k], k+1, F, lines[k]); } for( j = 0; j < npt; j++ ) { double errij = fabs(imagePoints[0][i][j].x*lines[1][j][0] + imagePoints[0][i][j].y*lines[1][j][1] + lines[1][j][2]) + fabs(imagePoints[1][i][j].x*lines[0][j][0] + imagePoints[1][i][j].y*lines[0][j][1] + lines[0][j][2]); err += errij; } npoints += npt; } fprintf(stdout,"average reprojection err = %f\n",err/npoints); cout.flush(); }
void CalibrationDialog::calibrate() { processingData_ = true; savedCalibration_ = false; QMessageBox mb(QMessageBox::Information, tr("Calibrating..."), tr("Operation in progress...")); mb.show(); QApplication::processEvents(); uSleep(100); // hack make sure the text in the QMessageBox is shown... QApplication::processEvents(); std::vector<std::vector<cv::Point3f> > objectPoints(1); cv::Size boardSize(ui_->spinBox_boardWidth->value(), ui_->spinBox_boardHeight->value()); float squareSize = ui_->doubleSpinBox_squareSize->value(); // compute board corner positions for( int i = 0; i < boardSize.height; ++i ) for( int j = 0; j < boardSize.width; ++j ) objectPoints[0].push_back(cv::Point3f(float( j*squareSize ), float( i*squareSize ), 0)); for(int id=0; id<(stereo_?2:1); ++id) { UINFO("Calibrating camera %d (samples=%d)", id, (int)imagePoints_[id].size()); objectPoints.resize(imagePoints_[id].size(), objectPoints[0]); //calibrate std::vector<cv::Mat> rvecs, tvecs; std::vector<float> reprojErrs; cv::Mat K, D; K = cv::Mat::eye(3,3,CV_64FC1); UINFO("calibrate!"); //Find intrinsic and extrinsic camera parameters double rms = cv::calibrateCamera(objectPoints, imagePoints_[id], imageSize_[id], K, D, rvecs, tvecs); UINFO("Re-projection error reported by calibrateCamera: %f", rms); // compute reprojection errors std::vector<cv::Point2f> imagePoints2; int i, totalPoints = 0; double totalErr = 0, err; reprojErrs.resize(objectPoints.size()); for( i = 0; i < (int)objectPoints.size(); ++i ) { cv::projectPoints( cv::Mat(objectPoints[i]), rvecs[i], tvecs[i], K, D, imagePoints2); err = cv::norm(cv::Mat(imagePoints_[id][i]), cv::Mat(imagePoints2), CV_L2); int n = (int)objectPoints[i].size(); reprojErrs[i] = (float) std::sqrt(err*err/n); totalErr += err*err; totalPoints += n; } double totalAvgErr = std::sqrt(totalErr/totalPoints); UINFO("avg re projection error = %f", totalAvgErr); cv::Mat P(3,4,CV_64FC1); P.at<double>(2,3) = 1; K.copyTo(P.colRange(0,3).rowRange(0,3)); std::cout << "cameraMatrix = " << K << std::endl; std::cout << "distCoeffs = " << D << std::endl; std::cout << "width = " << imageSize_[id].width << std::endl; std::cout << "height = " << imageSize_[id].height << std::endl; models_[id] = CameraModel(cameraName_.toStdString(), imageSize_[id], K, D, cv::Mat::eye(3,3,CV_64FC1), P); if(id == 0) { ui_->label_fx->setNum(models_[id].fx()); ui_->label_fy->setNum(models_[id].fy()); ui_->label_cx->setNum(models_[id].cx()); ui_->label_cy->setNum(models_[id].cy()); ui_->label_error->setNum(totalAvgErr); std::stringstream strK, strD, strR, strP; strK << models_[id].K(); strD << models_[id].D(); strR << models_[id].R(); strP << models_[id].P(); ui_->lineEdit_K->setText(strK.str().c_str()); ui_->lineEdit_D->setText(strD.str().c_str()); ui_->lineEdit_R->setText(strR.str().c_str()); ui_->lineEdit_P->setText(strP.str().c_str()); } else { ui_->label_fx_2->setNum(models_[id].fx()); ui_->label_fy_2->setNum(models_[id].fy()); ui_->label_cx_2->setNum(models_[id].cx()); ui_->label_cy_2->setNum(models_[id].cy()); ui_->label_error_2->setNum(totalAvgErr); std::stringstream strK, strD, strR, strP; strK << models_[id].K(); strD << models_[id].D(); strR << models_[id].R(); strP << models_[id].P(); ui_->lineEdit_K_2->setText(strK.str().c_str()); ui_->lineEdit_D_2->setText(strD.str().c_str()); ui_->lineEdit_R_2->setText(strR.str().c_str()); ui_->lineEdit_P_2->setText(strP.str().c_str()); } } if(stereo_ && models_[0].isValid() && models_[1].isValid()) { UINFO("stereo calibration (samples=%d)...", (int)stereoImagePoints_[0].size()); cv::Size imageSize = imageSize_[0].width > imageSize_[1].width?imageSize_[0]:imageSize_[1]; cv::Mat R, T, E, F; std::vector<std::vector<cv::Point3f> > objectPoints(1); cv::Size boardSize(ui_->spinBox_boardWidth->value(), ui_->spinBox_boardHeight->value()); float squareSize = ui_->doubleSpinBox_squareSize->value(); // compute board corner positions for( int i = 0; i < boardSize.height; ++i ) for( int j = 0; j < boardSize.width; ++j ) objectPoints[0].push_back(cv::Point3f(float( j*squareSize ), float( i*squareSize ), 0)); objectPoints.resize(stereoImagePoints_[0].size(), objectPoints[0]); // calibrate extrinsic #if CV_MAJOR_VERSION < 3 double rms = cv::stereoCalibrate( objectPoints, stereoImagePoints_[0], stereoImagePoints_[1], models_[0].K(), models_[0].D(), models_[1].K(), models_[1].D(), imageSize, R, T, E, F, cv::TermCriteria(cv::TermCriteria::COUNT+cv::TermCriteria::EPS, 100, 1e-5), cv::CALIB_FIX_INTRINSIC); #else double rms = cv::stereoCalibrate( objectPoints, stereoImagePoints_[0], stereoImagePoints_[1], models_[0].K(), models_[0].D(), models_[1].K(), models_[1].D(), imageSize, R, T, E, F, cv::CALIB_FIX_INTRINSIC, cv::TermCriteria(cv::TermCriteria::COUNT+cv::TermCriteria::EPS, 100, 1e-5)); #endif UINFO("stereo calibration... done with RMS error=%f", rms); double err = 0; int npoints = 0; std::vector<cv::Vec3f> lines[2]; UINFO("Computing avg re-projection error..."); for(unsigned int i = 0; i < stereoImagePoints_[0].size(); i++ ) { int npt = (int)stereoImagePoints_[0][i].size(); cv::Mat imgpt[2]; for(int k = 0; k < 2; k++ ) { imgpt[k] = cv::Mat(stereoImagePoints_[k][i]); cv::undistortPoints(imgpt[k], imgpt[k], models_[k].K(), models_[k].D(), cv::Mat(), models_[k].K()); computeCorrespondEpilines(imgpt[k], k+1, F, lines[k]); } for(int j = 0; j < npt; j++ ) { double errij = fabs(stereoImagePoints_[0][i][j].x*lines[1][j][0] + stereoImagePoints_[0][i][j].y*lines[1][j][1] + lines[1][j][2]) + fabs(stereoImagePoints_[1][i][j].x*lines[0][j][0] + stereoImagePoints_[1][i][j].y*lines[0][j][1] + lines[0][j][2]); err += errij; } npoints += npt; } double totalAvgErr = err/(double)npoints; UINFO("stereo avg re projection error = %f", totalAvgErr); cv::Mat R1, R2, P1, P2, Q; cv::Rect validRoi[2]; cv::stereoRectify(models_[0].K(), models_[0].D(), models_[1].K(), models_[1].D(), imageSize, R, T, R1, R2, P1, P2, Q, cv::CALIB_ZERO_DISPARITY, 0, imageSize, &validRoi[0], &validRoi[1]); UINFO("Valid ROI1 = %d,%d,%d,%d ROI2 = %d,%d,%d,%d newImageSize=%d/%d", validRoi[0].x, validRoi[0].y, validRoi[0].width, validRoi[0].height, validRoi[1].x, validRoi[1].y, validRoi[1].width, validRoi[1].height, imageSize.width, imageSize.height); if(imageSize_[0].width == imageSize_[1].width) { //Stereo, keep new extrinsic projection matrix stereoModel_ = StereoCameraModel( cameraName_.toStdString(), imageSize_[0], models_[0].K(), models_[0].D(), R1, P1, imageSize_[1], models_[1].K(), models_[1].D(), R2, P2, R, T, E, F); } else { //Kinect stereoModel_ = StereoCameraModel( cameraName_.toStdString(), imageSize_[0], models_[0].K(), models_[0].D(), cv::Mat::eye(3,3,CV_64FC1), models_[0].P(), imageSize_[1], models_[1].K(), models_[1].D(), cv::Mat::eye(3,3,CV_64FC1), models_[1].P(), R, T, E, F); } std::stringstream strR1, strP1, strR2, strP2; strR1 << stereoModel_.left().R(); strP1 << stereoModel_.left().P(); strR2 << stereoModel_.right().R(); strP2 << stereoModel_.right().P(); ui_->lineEdit_R->setText(strR1.str().c_str()); ui_->lineEdit_P->setText(strP1.str().c_str()); ui_->lineEdit_R_2->setText(strR2.str().c_str()); ui_->lineEdit_P_2->setText(strP2.str().c_str()); ui_->label_baseline->setNum(stereoModel_.baseline()); //ui_->label_error_stereo->setNum(totalAvgErr); } if(stereo_ && stereoModel_.left().isValid() && stereoModel_.right().isValid()&& (!ui_->label_baseline->isVisible() || stereoModel_.baseline() > 0.0)) { ui_->radioButton_rectified->setEnabled(true); ui_->radioButton_stereoRectified->setEnabled(true); ui_->radioButton_stereoRectified->setChecked(true); ui_->pushButton_save->setEnabled(true); } else if(models_[0].isValid()) { ui_->radioButton_rectified->setEnabled(true); ui_->radioButton_rectified->setChecked(true); ui_->pushButton_save->setEnabled(!stereo_); } UINFO("End calibration"); processingData_ = false; }
void StereoCalib(const vector<string>& imagelist, Size boardSize, bool useCalibrated=true, bool showRectified=true) { if( imagelist.size() % 2 != 0 ) { cout << "Error: the image list contains odd (non-even) number of elements\n"; return; } printf("board size: %d x %d", boardSize.width, boardSize.height); bool displayCorners = true; const int maxScale = 2; const float squareSize = 1.f; // Set this to your actual square size // ARRAY AND VECTOR STORAGE: vector<vector<Point2f> > imagePoints[2]; vector<vector<Point3f> > objectPoints; Size imageSize; int i, j, k, nimages = (int)imagelist.size()/2; imagePoints[0].resize(nimages); imagePoints[1].resize(nimages); vector<string> goodImageList; for( i = j = 0; i < nimages; i++ ) { for( k = 0; k < 2; k++ ) { const string& filename = imagelist[i*2+k]; Mat img = imread(filename, 0); if(img.empty()) break; if( imageSize == Size() ) imageSize = img.size(); else if( img.size() != imageSize ) { cout << "The image " << filename << " has the size different from the first image size. Skipping the pair\n"; break; } bool found = false; vector<Point2f>& corners = imagePoints[k][j]; for( int scale = 1; scale <= maxScale; scale++ ) { Mat timg; if( scale == 1 ) timg = img; else resize(img, timg, Size(), scale, scale); found = findChessboardCorners(timg, boardSize, corners, CV_CALIB_CB_ADAPTIVE_THRESH | CV_CALIB_CB_NORMALIZE_IMAGE); if( found ) { if( scale > 1 ) { Mat cornersMat(corners); cornersMat *= 1./scale; } break; } } if( displayCorners ) { cout << filename << endl; Mat cimg, cimg1; cvtColor(img, cimg, CV_GRAY2BGR); drawChessboardCorners(cimg, boardSize, corners, found); double sf = 640./MAX(img.rows, img.cols); resize(cimg, cimg1, Size(), sf, sf); imshow("corners", cimg1); char c = (char)waitKey(500); if( c == 27 || c == 'q' || c == 'Q' ) //Allow ESC to quit exit(-1); } else putchar('.'); if( !found ) break; cornerSubPix(img, corners, Size(11,11), Size(-1,-1), TermCriteria(CV_TERMCRIT_ITER+CV_TERMCRIT_EPS, 30, 0.01)); } if( k == 2 ) { goodImageList.push_back(imagelist[i*2]); goodImageList.push_back(imagelist[i*2+1]); j++; } } cout << j << " pairs have been successfully detected.\n"; nimages = j; if( nimages < 2 ) { cout << "Error: too little pairs to run the calibration\n"; return; } imagePoints[0].resize(nimages); imagePoints[1].resize(nimages); objectPoints.resize(nimages); for( i = 0; i < nimages; i++ ) { for( j = 0; j < boardSize.height; j++ ) for( k = 0; k < boardSize.width; k++ ) objectPoints[i].push_back(Point3f(j*squareSize, k*squareSize, 0)); } cout << "Running stereo calibration ...\n"; Mat cameraMatrix[2], distCoeffs[2]; cameraMatrix[0] = Mat::eye(3, 3, CV_64F); cameraMatrix[1] = Mat::eye(3, 3, CV_64F); Mat R, T, E, F; double rms = stereoCalibrate(objectPoints, imagePoints[0], imagePoints[1], cameraMatrix[0], distCoeffs[0], cameraMatrix[1], distCoeffs[1], imageSize, R, T, E, F, TermCriteria(CV_TERMCRIT_ITER+CV_TERMCRIT_EPS, 100, 1e-5), CV_CALIB_FIX_ASPECT_RATIO + CV_CALIB_ZERO_TANGENT_DIST + //CV_CALIB_SAME_FOCAL_LENGTH + CV_CALIB_RATIONAL_MODEL + CV_CALIB_FIX_K3 + CV_CALIB_FIX_K4 + CV_CALIB_FIX_K5); cout << "done with RMS error=" << rms << endl; // CALIBRATION QUALITY CHECK // because the output fundamental matrix implicitly // includes all the output information, // we can check the quality of calibration using the // epipolar geometry constraint: m2^t*F*m1=0 double err = 0; int npoints = 0; vector<Vec3f> lines[2]; for( i = 0; i < nimages; i++ ) { int npt = (int)imagePoints[0][i].size(); Mat imgpt[2]; for( k = 0; k < 2; k++ ) { imgpt[k] = Mat(imagePoints[k][i]); undistortPoints(imgpt[k], imgpt[k], cameraMatrix[k], distCoeffs[k], Mat(), cameraMatrix[k]); computeCorrespondEpilines(imgpt[k], k+1, F, lines[k]); } for( j = 0; j < npt; j++ ) { double errij = fabs(imagePoints[0][i][j].x*lines[1][j][0] + imagePoints[0][i][j].y*lines[1][j][1] + lines[1][j][2]) + fabs(imagePoints[1][i][j].x*lines[0][j][0] + imagePoints[1][i][j].y*lines[0][j][1] + lines[0][j][2]); err += errij; } npoints += npt; } cout << "average reprojection err = " << err/npoints << endl; // save intrinsic parameters FileStorage fs("calib/intrinsics.yml", CV_STORAGE_WRITE); if( fs.isOpened() ) { fs << "M1" << cameraMatrix[0] << "D1" << distCoeffs[0] << "M2" << cameraMatrix[1] << "D2" << distCoeffs[1]; fs.release(); } else cout << "Error: can not save the intrinsic parameters\n"; Mat R1, R2, P1, P2, Q; Rect validRoi[2]; stereoRectify(cameraMatrix[0], distCoeffs[0], cameraMatrix[1], distCoeffs[1], imageSize, R, T, R1, R2, P1, P2, Q, CALIB_ZERO_DISPARITY, 1, imageSize, &validRoi[0], &validRoi[1]); fs.open("calib/extrinsics.yml", CV_STORAGE_WRITE); if( fs.isOpened() ) { fs << "R" << R << "T" << T << "R1" << R1 << "R2" << R2 << "P1" << P1 << "P2" << P2 << "Q" << Q; fs.release(); } else cout << "Error: can not save the intrinsic parameters\n"; // OpenCV can handle left-right // or up-down camera arrangements bool isVerticalStereo = fabs(P2.at<double>(1, 3)) > fabs(P2.at<double>(0, 3)); // COMPUTE AND DISPLAY RECTIFICATION if( !showRectified ) return; Mat rmap[2][2]; // IF BY CALIBRATED (BOUGUET'S METHOD) if( useCalibrated ) { // we already computed everything } // OR ELSE HARTLEY'S METHOD else // use intrinsic parameters of each camera, but // compute the rectification transformation directly // from the fundamental matrix { vector<Point2f> allimgpt[2]; for( k = 0; k < 2; k++ ) { for( i = 0; i < nimages; i++ ) std::copy(imagePoints[k][i].begin(), imagePoints[k][i].end(), back_inserter(allimgpt[k])); } F = findFundamentalMat(Mat(allimgpt[0]), Mat(allimgpt[1]), FM_8POINT, 0, 0); Mat H1, H2; stereoRectifyUncalibrated(Mat(allimgpt[0]), Mat(allimgpt[1]), F, imageSize, H1, H2, 3); R1 = cameraMatrix[0].inv()*H1*cameraMatrix[0]; R2 = cameraMatrix[1].inv()*H2*cameraMatrix[1]; P1 = cameraMatrix[0]; P2 = cameraMatrix[1]; } //Precompute maps for cv::remap() initUndistortRectifyMap(cameraMatrix[0], distCoeffs[0], R1, P1, imageSize, CV_16SC2, rmap[0][0], rmap[0][1]); initUndistortRectifyMap(cameraMatrix[1], distCoeffs[1], R2, P2, imageSize, CV_16SC2, rmap[1][0], rmap[1][1]); Mat canvas; double sf; int w, h; if( !isVerticalStereo ) { sf = 600./MAX(imageSize.width, imageSize.height); w = cvRound(imageSize.width*sf); h = cvRound(imageSize.height*sf); canvas.create(h, w*2, CV_8UC3); } else { sf = 300./MAX(imageSize.width, imageSize.height); w = cvRound(imageSize.width*sf); h = cvRound(imageSize.height*sf); canvas.create(h*2, w, CV_8UC3); } for( i = 0; i < nimages; i++ ) { for( k = 0; k < 2; k++ ) { Mat img = imread(goodImageList[i*2+k], 0), rimg, cimg; remap(img, rimg, rmap[k][0], rmap[k][1], CV_INTER_LINEAR); cvtColor(rimg, cimg, CV_GRAY2BGR); Mat canvasPart = !isVerticalStereo ? canvas(Rect(w*k, 0, w, h)) : canvas(Rect(0, h*k, w, h)); resize(cimg, canvasPart, canvasPart.size(), 0, 0, CV_INTER_AREA); if( useCalibrated ) { Rect vroi(cvRound(validRoi[k].x*sf), cvRound(validRoi[k].y*sf), cvRound(validRoi[k].width*sf), cvRound(validRoi[k].height*sf)); rectangle(canvasPart, vroi, Scalar(0,0,255), 3, 8); } } if( !isVerticalStereo ) for( j = 0; j < canvas.rows; j += 16 ) line(canvas, Point(0, j), Point(canvas.cols, j), Scalar(0, 255, 0), 1, 8); else for( j = 0; j < canvas.cols; j += 16 ) line(canvas, Point(j, 0), Point(j, canvas.rows), Scalar(0, 255, 0), 1, 8); imshow("rectified", canvas); char c = (char)waitKey(); if( c == 27 || c == 'q' || c == 'Q' ) break; } }