5
Tôi đang cố hiệu chỉnh hai máy ảnh Điểm xám (Blackfly) của mình để có được tầm nhìn âm thanh nổi. Tôi đang sử dụng tệp stereo_calib.cpp hướng dẫn đi kèm với OpenCV (mã bên dưới). Đối với một số lý do, tôi nhận được kết quả thực sự xấu (RMS lỗi = 4.49756 và reprojection trung bình err = 8.06533) và tất cả các hình ảnh sửa chữa của tôi đi ra màu xám. Tôi nghĩ rằng vấn đề của tôi là tôi không chọn đúng cờ cho hàm stereoCalibrate(), nhưng tôi đã thử nhiều kết hợp khác nhau và tốt nhất là hình ảnh được chỉnh sửa sẽ bị biến dạng.Hiệu chỉnh Máy ảnh Stereo OpenCV/Chỉnh sửa hình ảnh
Dưới đây là một liên kết đến những hình ảnh tôi đã sử dụng và một mẫu sửa chữa cặp: https://www.dropbox.com/sh/5wp31o8xcn6vmjl/AAADAfGiaT_NyXEB3zMpcEvVa#/
Bất kỳ trợ giúp sẽ được đánh giá cao !!
static 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;
}
bool displayCorners = true;//false;//true;
const int maxScale = 1;//2;
const float squareSize = 1.8;
//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;
int i, j, k, nimages = (int)imagelist.size();
cout << "nimages: " << nimages << "\n";
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, COLOR_GRAY2BGR);
drawChessboardCorners(cimg, boardSize, corners, found);
double sf = 1280./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) {
cout << "!found\n";
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));
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_K2);
CV_CALIB_FIX_K3 + CV_CALIB_FIX_K4 + CV_CALIB_FIX_K5);
//CV_CALIB_FIX_K1 + CV_CALIB_FIX_K2 + CV_CALIB_FIX_K3 + CV_CALIB_FIX_K4 + CV_CALIB_FIX_K5);
cout << "done with RMS error=" << rms << endl;
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("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]);
CALIB_ZERO_DISPARITY, 0, imageSize, &validRoi[0], &validRoi[1]);
fs.open("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));
bool isVerticalStereo = false;
// 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 = 600./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, COLOR_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;
}
}