/* -------------------------------------------------------
checkerBoardCameraCalibration
------------------------------------------------------- */
bool mrpt::vision::checkerBoardCameraCalibration(
TCalibrationImageList &images,
unsigned int check_size_x,
unsigned int check_size_y,
double check_squares_length_X_meters,
double check_squares_length_Y_meters,
mrpt::utils::TCamera &out_camera_params,
bool normalize_image,
double *out_MSE,
bool skipDrawDetectedImgs,
bool useScaramuzzaAlternativeDetector
)
{
#if MRPT_HAS_OPENCV
try
{
ASSERT_(check_size_x>2)
ASSERT_(check_size_y>2)
ASSERT_(check_squares_length_X_meters>0)
ASSERT_(check_squares_length_Y_meters>0)
if (images.size()<1)
{
std::cout << "ERROR: No input images." << std::endl;
return false;
}
const unsigned CORNERS_COUNT = check_size_x * check_size_y;
const CvSize check_size = cvSize(check_size_x, check_size_y);
// First: Assure all images are loaded:
// -------------------------------------------
TCalibrationImageList::iterator it;
for (it=images.begin();it!=images.end();it++)
{
TImageCalibData &dat = it->second;
dat.projectedPoints_distorted.clear(); // Clear reprojected points.
dat.projectedPoints_undistorted.clear();
// Skip if images are marked as "externalStorage":
if (!dat.img_original.isExternallyStored() && !mrpt::system::extractFileExtension(it->first).empty() )
{
if (!dat.img_original.loadFromFile(it->first))
THROW_EXCEPTION_CUSTOM_MSG1("Error reading image: %s",it->first.c_str());
dat.img_checkboard = dat.img_original;
dat.img_rectified = dat.img_original;
}
}
// For each image, find checkerboard corners:
// -----------------------------------------------
//const unsigned int N = images.size();
unsigned int i;
vector<CvPoint2D64f> corners_list; // = new CvPoint2D32f[ N * CORNERS_COUNT];
unsigned int valid_detected_imgs = 0;
CvSize imgSize = cvSize(0,0);
vector<string> pointsIdx2imageFile;
int find_chess_flags = CV_CALIB_CB_ADAPTIVE_THRESH;
if (normalize_image)
find_chess_flags |= CV_CALIB_CB_NORMALIZE_IMAGE;
for (i=0,it=images.begin();it!=images.end();it++,i++)
{
TImageCalibData &dat = it->second;
// Make grayscale version:
const CImage img_gray( dat.img_original, FAST_REF_OR_CONVERT_TO_GRAY );
if (!i)
{
imgSize = cvSize(img_gray.getWidth(),img_gray.getHeight() );
out_camera_params.ncols = imgSize.width;
out_camera_params.nrows = imgSize.height;
}
else
{
if (imgSize.height != (int)img_gray.getHeight() || imgSize.width != (int)img_gray.getWidth())
{
std::cout << "ERROR: All the images must have the same size" << std::endl;
return false;
}
}
// Try with expanded versions of the image if it fails to detect the checkerboard:
unsigned corners_count;
bool corners_found=false;
corners_count = CORNERS_COUNT;
corners_list.resize( (1+valid_detected_imgs)*CORNERS_COUNT );
dat.detected_corners.clear();
// Do detection (this includes the "refine corners" with cvFindCornerSubPix):
vector<TPixelCoordf> detectedCoords;
corners_found = mrpt::vision::findChessboardCorners(
img_gray,
detectedCoords,
check_size_x,check_size_y,
normalize_image, // normalize_image
useScaramuzzaAlternativeDetector
);
corners_count = detectedCoords.size();
// Copy the data into the overall array of coords:
ASSERT_(detectedCoords.size()<=CORNERS_COUNT);
for (size_t p=0;p<detectedCoords.size();p++)
{
corners_list[valid_detected_imgs*CORNERS_COUNT+p].x = detectedCoords[p].x;
corners_list[valid_detected_imgs*CORNERS_COUNT+p].y = detectedCoords[p].y;
}
if (corners_found && corners_count!=CORNERS_COUNT)
corners_found = false;
cout << format("Img %s: %s\n", mrpt::system::extractFileName(it->first).c_str() , corners_found ? "DETECTED" : "NOT DETECTED" );
if( corners_found )
{
// save the corners in the data structure:
int x, y;
unsigned int k;
for( y = 0, k = 0; y < check_size.height; y++ )
for( x = 0; x < check_size.width; x++, k++ )
dat.detected_corners.push_back( mrpt::utils::TPixelCoordf( corners_list[valid_detected_imgs*CORNERS_COUNT + k].x, corners_list[valid_detected_imgs*CORNERS_COUNT + k].y ) );
// Draw the checkerboard in the corresponding image:
// ----------------------------------------------------
if ( !dat.img_original.isExternallyStored() )
{
const int r = 4;
CvPoint prev_pt= cvPoint(0, 0);
const int line_max = 8;
CvScalar line_colors[8];
line_colors[0] = CV_RGB(255,0,0);
line_colors[1] = CV_RGB(255,128,0);
line_colors[2] = CV_RGB(255,128,0);
line_colors[3] = CV_RGB(200,200,0);
line_colors[4] = CV_RGB(0,255,0);
line_colors[5] = CV_RGB(0,200,200);
line_colors[6] = CV_RGB(0,0,255);
line_colors[7] = CV_RGB(255,0,255);
// Checkboad as color image:
dat.img_original.colorImage( dat.img_checkboard );
void *rgb_img = dat.img_checkboard.getAs<IplImage>();
for( y = 0, k = 0; y < check_size.height; y++ )
{
CvScalar color = line_colors[y % line_max];
for( x = 0; x < check_size.width; x++, k++ )
{
CvPoint pt;
pt.x = cvRound(corners_list[valid_detected_imgs*CORNERS_COUNT + k].x);
pt.y = cvRound(corners_list[valid_detected_imgs*CORNERS_COUNT + k].y);
if( k != 0 ) cvLine( rgb_img, prev_pt, pt, color );
cvLine( rgb_img,
cvPoint( pt.x - r, pt.y - r ),
cvPoint( pt.x + r, pt.y + r ), color );
cvLine( rgb_img,
cvPoint( pt.x - r, pt.y + r),
cvPoint( pt.x + r, pt.y - r), color );
cvCircle( rgb_img, pt, r+1, color );
prev_pt = pt;
}
}
}
}
if( corners_found )
{
pointsIdx2imageFile.push_back( it->first );
valid_detected_imgs++;
}
} // end find corners
std::cout << valid_detected_imgs << " valid images." << std::endl;
if (!valid_detected_imgs)
{
std::cout << "ERROR: No valid images. Perhaps the checkerboard size is incorrect?" << std::endl;
return false;
}
// ---------------------------------------------
// Calculate the camera parameters
// ---------------------------------------------
// Was: FillEtalonObjPoints
vector<CvPoint3D64f> obj_points( valid_detected_imgs * CORNERS_COUNT );
{
unsigned int y,k;
for( y = 0, k = 0; y < check_size_y; y++ )
{
for( unsigned int x = 0; x < check_size_x; x++, k++ )
{
obj_points[k].x =-check_squares_length_X_meters * x; // The "-" is for convenience, so the camera poses appear with Z>0
obj_points[k].y = check_squares_length_Y_meters * y;
obj_points[k].z = 0;
}
}
}
// Repeat the pattern N times:
for( i= 1; i< valid_detected_imgs; i++ )
memcpy( &obj_points[CORNERS_COUNT*i], &obj_points[0], CORNERS_COUNT*sizeof(obj_points[0]));
// Number of detected points in each image (constant):
vector<int> numsPoints(valid_detected_imgs, (int)CORNERS_COUNT );
double proj_matrix[9];
double distortion[4];
vector<CvPoint3D64f> transVects( valid_detected_imgs );
vector<double> rotMatrs( valid_detected_imgs * 9 );
// Calibrate camera
cvCalibrateCamera_64d(
valid_detected_imgs,
&numsPoints[0],
imgSize,
&corners_list[0],
&obj_points[0],
distortion,
proj_matrix,
(double*)&transVects[0],
&rotMatrs[0],
0 );
// Load matrix:
out_camera_params.intrinsicParams = CMatrixDouble33( proj_matrix );
out_camera_params.dist.assign(0);
for (int i=0;i<4;i++)
out_camera_params.dist[i] = distortion[i];
// Load camera poses:
for (i=0;i<valid_detected_imgs;i++)
{
const double *R = &rotMatrs[9*i];
CMatrixDouble HM(4,4);
HM.zeros();
HM(3,3)=1;
HM(0,0)=R[0];
HM(1,0)=R[3];
HM(2,0)=R[6];
HM(0,1)=R[1];
HM(1,1)=R[4];
HM(2,1)=R[7];
HM(0,2)=R[2];
HM(1,2)=R[5];
HM(2,2)=R[8];
HM(0,3)=transVects[i].x;
HM(1,3)=transVects[i].y;
HM(2,3)=transVects[i].z;
CPose3D p = CPose3D(0,0,0) - CPose3D(HM);
images[ pointsIdx2imageFile[i] ].reconstructed_camera_pose = p;
std::cout << "Img: " << mrpt::system::extractFileName(pointsIdx2imageFile[i]) << ": " << p << std::endl;
}
{
CConfigFileMemory cfg;
out_camera_params.saveToConfigFile("CAMERA_PARAMS",cfg);
std::cout << cfg.getContent() << std::endl;
}
// ----------------------------------------
// Undistort images:
// ----------------------------------------
for (it=images.begin();it!=images.end();it++)
{
TImageCalibData &dat = it->second;
if (!dat.img_original.isExternallyStored())
dat.img_original.rectifyImage( dat.img_rectified, out_camera_params);
} // end undistort
// -----------------------------------------------
// Reproject points to measure the fit sqr error
// -----------------------------------------------
double sqrErr = 0;
for (i=0;i<valid_detected_imgs;i++)
{
TImageCalibData & dat = images[ pointsIdx2imageFile[i] ];
if (dat.detected_corners.size()!=CORNERS_COUNT) continue;
// Reproject all the points into pixel coordinates:
// -----------------------------------------------------
vector<TPoint3D> lstPatternPoints(CORNERS_COUNT); // Points as seen from the camera:
for (unsigned int p=0;p<CORNERS_COUNT;p++)
lstPatternPoints[p] = TPoint3D(obj_points[p].x,obj_points[p].y,obj_points[p].z);
vector<TPixelCoordf> &projectedPoints = dat.projectedPoints_undistorted;
vector<TPixelCoordf> &projectedPoints_distorted = dat.projectedPoints_distorted;
vision::pinhole::projectPoints_no_distortion(
lstPatternPoints, // Input points
dat.reconstructed_camera_pose,
out_camera_params.intrinsicParams, // calib matrix
projectedPoints // Output points in pixels
);
vision::pinhole::projectPoints_with_distortion(
lstPatternPoints, // Input points
dat.reconstructed_camera_pose,
out_camera_params.intrinsicParams, // calib matrix
out_camera_params.getDistortionParamsAsVector(),
projectedPoints_distorted// Output points in pixels
);
ASSERT_(projectedPoints.size()==CORNERS_COUNT);
ASSERT_(projectedPoints_distorted.size()==CORNERS_COUNT);
for (unsigned int p=0;p<CORNERS_COUNT;p++)
{
const double px = projectedPoints[p].x;
const double py = projectedPoints[p].y;
const double px_d = projectedPoints_distorted[p].x;
const double py_d = projectedPoints_distorted[p].y;
// Only draw if the img is NOT external:
if (!dat.img_original.isExternallyStored())
{
if( px >= 0 && px < imgSize.width && py >= 0 && py < imgSize.height )
cvCircle( dat.img_rectified.getAs<IplImage>(), cvPoint(px,py), 4, CV_RGB(0,0,255) );
}
// Accumulate error:
sqrErr+=square(px_d-dat.detected_corners[p].x)+square(py_d-dat.detected_corners[p].y); // Error relative to the original (distorted) image.
}
}
if (valid_detected_imgs)
{
sqrErr /= CORNERS_COUNT*valid_detected_imgs;
std::cout << "Average err. of reprojection: " << sqrt(sqrErr) << " pixels" << std::endl;
}
if(out_MSE) *out_MSE = sqrt(sqrErr);
return true;
}
catch(std::exception &e)
{
std::cout << e.what() << std::endl;
return false;
}
#else
THROW_EXCEPTION("Function not available: MRPT was compiled without OpenCV")
#endif
}
/* -------------------------------------------------------
checkerBoardCameraCalibration
------------------------------------------------------- */
bool mrpt::vision::checkerBoardCameraCalibration(
TCalibrationImageList &images,
unsigned int check_size_x,
unsigned int check_size_y,
double check_squares_length_X_meters,
double check_squares_length_Y_meters,
mrpt::utils::TCamera &out_camera_params,
bool normalize_image,
double *out_MSE,
bool skipDrawDetectedImgs,
bool useScaramuzzaAlternativeDetector
)
{
MRPT_UNUSED_PARAM(skipDrawDetectedImgs);
#if MRPT_HAS_OPENCV
try
{
ASSERT_(check_size_x>2)
ASSERT_(check_size_y>2)
ASSERT_(check_squares_length_X_meters>0)
ASSERT_(check_squares_length_Y_meters>0)
if (images.size()<1)
{
std::cout << "ERROR: No input images." << std::endl;
return false;
}
const unsigned CORNERS_COUNT = check_size_x * check_size_y;
const CvSize check_size = cvSize(check_size_x, check_size_y);
// Fill the pattern of expected pattern points only once out of the loop:
vector<cv::Point3f> pattern_obj_points(CORNERS_COUNT);
{
unsigned int y,k;
for( y = 0, k = 0; y < check_size_y; y++ )
{
for( unsigned int x = 0; x < check_size_x; x++, k++ )
{
pattern_obj_points[k].x =-check_squares_length_X_meters * x; // The "-" is for convenience, so the camera poses appear with Z>0
pattern_obj_points[k].y = check_squares_length_Y_meters * y;
pattern_obj_points[k].z = 0;
}
}
}
// First: Assure all images are loaded:
// -------------------------------------------
TCalibrationImageList::iterator it;
for (it=images.begin();it!=images.end();++it)
{
TImageCalibData &dat = it->second;
dat.projectedPoints_distorted.clear(); // Clear reprojected points.
dat.projectedPoints_undistorted.clear();
// Skip if images are marked as "externalStorage":
if (!dat.img_original.isExternallyStored() && !mrpt::system::extractFileExtension(it->first).empty() )
{
if (!dat.img_original.loadFromFile(it->first))
THROW_EXCEPTION_CUSTOM_MSG1("Error reading image: %s",it->first.c_str());
dat.img_checkboard = dat.img_original;
dat.img_rectified = dat.img_original;
}
}
// For each image, find checkerboard corners:
// -----------------------------------------------
vector<vector<cv::Point3f> > objectPoints; // final container for detected stuff
vector<vector<cv::Point2f> > imagePoints; // final container for detected stuff
unsigned int valid_detected_imgs = 0;
vector<string> pointsIdx2imageFile;
cv::Size imgSize(0,0);
unsigned int i;
for (i=0,it=images.begin();it!=images.end();it++,i++)
{
TImageCalibData &dat = it->second;
// Make grayscale version:
const CImage img_gray( dat.img_original, FAST_REF_OR_CONVERT_TO_GRAY );
if (!i)
{
imgSize = cv::Size(img_gray.getWidth(),img_gray.getHeight() );
out_camera_params.ncols = imgSize.width;
out_camera_params.nrows = imgSize.height;
}
else
{
if (imgSize.height != (int)img_gray.getHeight() || imgSize.width != (int)img_gray.getWidth())
{
std::cout << "ERROR: All the images must have the same size" << std::endl;
return false;
}
}
// Try with expanded versions of the image if it fails to detect the checkerboard:
unsigned corners_count;
bool corners_found=false;
corners_count = CORNERS_COUNT;
vector<cv::Point2f> this_img_pts(CORNERS_COUNT); // Temporary buffer for points, to be added if the points pass the checks.
dat.detected_corners.clear();
// Do detection (this includes the "refine corners" with cvFindCornerSubPix):
vector<TPixelCoordf> detectedCoords;
corners_found = mrpt::vision::findChessboardCorners(
img_gray,
detectedCoords,
check_size_x,check_size_y,
normalize_image, // normalize_image
useScaramuzzaAlternativeDetector
);
corners_count = detectedCoords.size();
// Copy the data into the overall array of coords:
ASSERT_(detectedCoords.size()<=CORNERS_COUNT);
for (size_t p=0;p<detectedCoords.size();p++)
{
this_img_pts[p].x = detectedCoords[p].x;
this_img_pts[p].y = detectedCoords[p].y;
}
if (corners_found && corners_count!=CORNERS_COUNT)
corners_found = false;
cout << format("Img %s: %s\n", mrpt::system::extractFileName(it->first).c_str() , corners_found ? "DETECTED" : "NOT DETECTED" );
if( corners_found )
{
// save the corners in the data structure:
int x, y;
unsigned int k;
for( y = 0, k = 0; y < check_size.height; y++ )
for( x = 0; x < check_size.width; x++, k++ )
dat.detected_corners.push_back( mrpt::utils::TPixelCoordf( this_img_pts[k].x, this_img_pts[k].y ) );
// Draw the checkerboard in the corresponding image:
// ----------------------------------------------------
if ( !dat.img_original.isExternallyStored() )
{
const int r = 4;
CvPoint prev_pt= cvPoint(0, 0);
const int line_max = 8;
CvScalar line_colors[8];
line_colors[0] = CV_RGB(255,0,0);
line_colors[1] = CV_RGB(255,128,0);
line_colors[2] = CV_RGB(255,128,0);
line_colors[3] = CV_RGB(200,200,0);
line_colors[4] = CV_RGB(0,255,0);
line_colors[5] = CV_RGB(0,200,200);
line_colors[6] = CV_RGB(0,0,255);
line_colors[7] = CV_RGB(255,0,255);
// Checkboad as color image:
dat.img_original.colorImage( dat.img_checkboard );
void *rgb_img = dat.img_checkboard.getAs<IplImage>();
for( y = 0, k = 0; y < check_size.height; y++ )
{
CvScalar color = line_colors[y % line_max];
for( x = 0; x < check_size.width; x++, k++ )
{
CvPoint pt;
pt.x = cvRound(this_img_pts[k].x);
pt.y = cvRound(this_img_pts[k].y);
if( k != 0 ) cvLine( rgb_img, prev_pt, pt, color );
cvLine( rgb_img,
cvPoint( pt.x - r, pt.y - r ),
cvPoint( pt.x + r, pt.y + r ), color );
cvLine( rgb_img,
cvPoint( pt.x - r, pt.y + r),
cvPoint( pt.x + r, pt.y - r), color );
cvCircle( rgb_img, pt, r+1, color );
prev_pt = pt;
}
}
}
// Accept this image as good:
pointsIdx2imageFile.push_back( it->first );
imagePoints.push_back( this_img_pts );
objectPoints.push_back( pattern_obj_points );
valid_detected_imgs++;
}
} // end find corners
std::cout << valid_detected_imgs << " valid images." << std::endl;
if (!valid_detected_imgs)
{
std::cout << "ERROR: No valid images. Perhaps the checkerboard size is incorrect?" << std::endl;
return false;
}
// ---------------------------------------------
// Calculate the camera parameters
// ---------------------------------------------
// Calibrate camera
cv::Mat cameraMatrix, distCoeffs(1,5,CV_64F,cv::Scalar::all(0));
vector<cv::Mat> rvecs, tvecs;
const double cv_calib_err =
cv::calibrateCamera(
objectPoints,imagePoints,imgSize,
cameraMatrix, distCoeffs, rvecs, tvecs,
0 /*flags*/ );
// Load matrix:
out_camera_params.intrinsicParams = CMatrixDouble33( cameraMatrix.ptr<double>() );
out_camera_params.dist.assign(0);
for (int i=0;i<5;i++)
out_camera_params.dist[i] = distCoeffs.ptr<double>()[i];
// Load camera poses:
for (i=0;i<valid_detected_imgs;i++)
{
CMatrixDouble44 HM;
HM.zeros();
HM(3,3)=1;
{
// Convert rotation vectors -> rot matrices:
cv::Mat cv_rot;
cv::Rodrigues(rvecs[i],cv_rot);
Eigen::Matrix3d rot;
cv::my_cv2eigen(cv_rot, rot );
HM.block<3,3>(0,0) = rot;
}
{
Eigen::Matrix<double,3,1> trans;
cv::my_cv2eigen(tvecs[i], trans );
HM.block<3,1>(0,3) = trans;
}
CPose3D p = CPose3D(0,0,0) - CPose3D(HM);
images[ pointsIdx2imageFile[i] ].reconstructed_camera_pose = p;
std::cout << "Img: " << mrpt::system::extractFileName(pointsIdx2imageFile[i]) << ": " << p << std::endl;
}
{
CConfigFileMemory cfg;
out_camera_params.saveToConfigFile("CAMERA_PARAMS",cfg);
std::cout << cfg.getContent() << std::endl;
}
// ----------------------------------------
// Undistort images:
// ----------------------------------------
for (it=images.begin();it!=images.end();++it)
{
TImageCalibData &dat = it->second;
if (!dat.img_original.isExternallyStored())
dat.img_original.rectifyImage( dat.img_rectified, out_camera_params);
} // end undistort
// -----------------------------------------------
// Reproject points to measure the fit sqr error
// -----------------------------------------------
double sqrErr = 0;
for (i=0;i<valid_detected_imgs;i++)
{
TImageCalibData & dat = images[ pointsIdx2imageFile[i] ];
if (dat.detected_corners.size()!=CORNERS_COUNT) continue;
// Reproject all the points into pixel coordinates:
// -----------------------------------------------------
vector<TPoint3D> lstPatternPoints(CORNERS_COUNT); // Points as seen from the camera:
for (unsigned int p=0;p<CORNERS_COUNT;p++)
lstPatternPoints[p] = TPoint3D(pattern_obj_points[p].x,pattern_obj_points[p].y,pattern_obj_points[p].z);
vector<TPixelCoordf> &projectedPoints = dat.projectedPoints_undistorted;
vector<TPixelCoordf> &projectedPoints_distorted = dat.projectedPoints_distorted;
vision::pinhole::projectPoints_no_distortion(
lstPatternPoints, // Input points
dat.reconstructed_camera_pose,
out_camera_params.intrinsicParams, // calib matrix
projectedPoints // Output points in pixels
);
vision::pinhole::projectPoints_with_distortion(
lstPatternPoints, // Input points
dat.reconstructed_camera_pose,
out_camera_params.intrinsicParams, // calib matrix
out_camera_params.getDistortionParamsAsVector(),
projectedPoints_distorted// Output points in pixels
);
ASSERT_(projectedPoints.size()==CORNERS_COUNT);
ASSERT_(projectedPoints_distorted.size()==CORNERS_COUNT);
for (unsigned int p=0;p<CORNERS_COUNT;p++)
{
const double px = projectedPoints[p].x;
const double py = projectedPoints[p].y;
const double px_d = projectedPoints_distorted[p].x;
const double py_d = projectedPoints_distorted[p].y;
// Only draw if the img is NOT external:
if (!dat.img_original.isExternallyStored())
{
if( px >= 0 && px < imgSize.width && py >= 0 && py < imgSize.height )
cvCircle( dat.img_rectified.getAs<IplImage>(), cvPoint(px,py), 4, CV_RGB(0,0,255) );
}
// Accumulate error:
sqrErr+=square(px_d-dat.detected_corners[p].x)+square(py_d-dat.detected_corners[p].y); // Error relative to the original (distorted) image.
}
}
if (valid_detected_imgs)
{
sqrErr /= CORNERS_COUNT*valid_detected_imgs;
std::cout << "Average err. of reprojection: " << sqrt(sqrErr) << " pixels (OpenCV error=" << cv_calib_err << ")\n";
}
if(out_MSE) *out_MSE = sqrt(sqrErr);
return true;
}
catch(std::exception &e)
{
std::cout << e.what() << std::endl;
return false;
}
#else
THROW_EXCEPTION("Function not available: MRPT was compiled without OpenCV")
#endif
}