This source file includes following definitions.
- print_help
- saveXYZ
- main
#include "opencv2/calib3d/calib3d.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/core/utility.hpp"
#include <stdio.h>
using namespace cv;
static void print_help()
{
printf("\nDemo stereo matching converting L and R images into disparity and point clouds\n");
printf("\nUsage: stereo_match <left_image> <right_image> [--algorithm=bm|sgbm|hh] [--blocksize=<block_size>]\n"
"[--max-disparity=<max_disparity>] [--scale=scale_factor>] [-i <intrinsic_filename>] [-e <extrinsic_filename>]\n"
"[--no-display] [-o <disparity_image>] [-p <point_cloud_file>]\n");
}
static void saveXYZ(const char* filename, const Mat& mat)
{
const double max_z = 1.0e4;
FILE* fp = fopen(filename, "wt");
for(int y = 0; y < mat.rows; y++)
{
for(int x = 0; x < mat.cols; x++)
{
Vec3f point = mat.at<Vec3f>(y, x);
if(fabs(point[2] - max_z) < FLT_EPSILON || fabs(point[2]) > max_z) continue;
fprintf(fp, "%f %f %f\n", point[0], point[1], point[2]);
}
}
fclose(fp);
}
int main(int argc, char** argv)
{
const char* algorithm_opt = "--algorithm=";
const char* maxdisp_opt = "--max-disparity=";
const char* blocksize_opt = "--blocksize=";
const char* nodisplay_opt = "--no-display";
const char* scale_opt = "--scale=";
if(argc < 3)
{
print_help();
return 0;
}
const char* img1_filename = 0;
const char* img2_filename = 0;
const char* intrinsic_filename = 0;
const char* extrinsic_filename = 0;
const char* disparity_filename = 0;
const char* point_cloud_filename = 0;
enum { STEREO_BM=0, STEREO_SGBM=1, STEREO_HH=2, STEREO_VAR=3 };
int alg = STEREO_SGBM;
int SADWindowSize = 0, numberOfDisparities = 0;
bool no_display = false;
float scale = 1.f;
Ptr<StereoBM> bm = StereoBM::create(16,9);
Ptr<StereoSGBM> sgbm = StereoSGBM::create(0,16,3);
for( int i = 1; i < argc; i++ )
{
if( argv[i][0] != '-' )
{
if( !img1_filename )
img1_filename = argv[i];
else
img2_filename = argv[i];
}
else if( strncmp(argv[i], algorithm_opt, strlen(algorithm_opt)) == 0 )
{
char* _alg = argv[i] + strlen(algorithm_opt);
alg = strcmp(_alg, "bm") == 0 ? STEREO_BM :
strcmp(_alg, "sgbm") == 0 ? STEREO_SGBM :
strcmp(_alg, "hh") == 0 ? STEREO_HH :
strcmp(_alg, "var") == 0 ? STEREO_VAR : -1;
if( alg < 0 )
{
printf("Command-line parameter error: Unknown stereo algorithm\n\n");
print_help();
return -1;
}
}
else if( strncmp(argv[i], maxdisp_opt, strlen(maxdisp_opt)) == 0 )
{
if( sscanf( argv[i] + strlen(maxdisp_opt), "%d", &numberOfDisparities ) != 1 ||
numberOfDisparities < 1 || numberOfDisparities % 16 != 0 )
{
printf("Command-line parameter error: The max disparity (--maxdisparity=<...>) must be a positive integer divisible by 16\n");
print_help();
return -1;
}
}
else if( strncmp(argv[i], blocksize_opt, strlen(blocksize_opt)) == 0 )
{
if( sscanf( argv[i] + strlen(blocksize_opt), "%d", &SADWindowSize ) != 1 ||
SADWindowSize < 1 || SADWindowSize % 2 != 1 )
{
printf("Command-line parameter error: The block size (--blocksize=<...>) must be a positive odd number\n");
return -1;
}
}
else if( strncmp(argv[i], scale_opt, strlen(scale_opt)) == 0 )
{
if( sscanf( argv[i] + strlen(scale_opt), "%f", &scale ) != 1 || scale < 0 )
{
printf("Command-line parameter error: The scale factor (--scale=<...>) must be a positive floating-point number\n");
return -1;
}
}
else if( strcmp(argv[i], nodisplay_opt) == 0 )
no_display = true;
else if( strcmp(argv[i], "-i" ) == 0 )
intrinsic_filename = argv[++i];
else if( strcmp(argv[i], "-e" ) == 0 )
extrinsic_filename = argv[++i];
else if( strcmp(argv[i], "-o" ) == 0 )
disparity_filename = argv[++i];
else if( strcmp(argv[i], "-p" ) == 0 )
point_cloud_filename = argv[++i];
else
{
printf("Command-line parameter error: unknown option %s\n", argv[i]);
return -1;
}
}
if( !img1_filename || !img2_filename )
{
printf("Command-line parameter error: both left and right images must be specified\n");
return -1;
}
if( (intrinsic_filename != 0) ^ (extrinsic_filename != 0) )
{
printf("Command-line parameter error: either both intrinsic and extrinsic parameters must be specified, or none of them (when the stereo pair is already rectified)\n");
return -1;
}
if( extrinsic_filename == 0 && point_cloud_filename )
{
printf("Command-line parameter error: extrinsic and intrinsic parameters must be specified to compute the point cloud\n");
return -1;
}
int color_mode = alg == STEREO_BM ? 0 : -1;
Mat img1 = imread(img1_filename, color_mode);
Mat img2 = imread(img2_filename, color_mode);
if (img1.empty())
{
printf("Command-line parameter error: could not load the first input image file\n");
return -1;
}
if (img2.empty())
{
printf("Command-line parameter error: could not load the second input image file\n");
return -1;
}
if (scale != 1.f)
{
Mat temp1, temp2;
int method = scale < 1 ? INTER_AREA : INTER_CUBIC;
resize(img1, temp1, Size(), scale, scale, method);
img1 = temp1;
resize(img2, temp2, Size(), scale, scale, method);
img2 = temp2;
}
Size img_size = img1.size();
Rect roi1, roi2;
Mat Q;
if( intrinsic_filename )
{
FileStorage fs(intrinsic_filename, FileStorage::READ);
if(!fs.isOpened())
{
printf("Failed to open file %s\n", intrinsic_filename);
return -1;
}
Mat M1, D1, M2, D2;
fs["M1"] >> M1;
fs["D1"] >> D1;
fs["M2"] >> M2;
fs["D2"] >> D2;
M1 *= scale;
M2 *= scale;
fs.open(extrinsic_filename, FileStorage::READ);
if(!fs.isOpened())
{
printf("Failed to open file %s\n", extrinsic_filename);
return -1;
}
Mat R, T, R1, P1, R2, P2;
fs["R"] >> R;
fs["T"] >> T;
stereoRectify( M1, D1, M2, D2, img_size, R, T, R1, R2, P1, P2, Q, CALIB_ZERO_DISPARITY, -1, img_size, &roi1, &roi2 );
Mat map11, map12, map21, map22;
initUndistortRectifyMap(M1, D1, R1, P1, img_size, CV_16SC2, map11, map12);
initUndistortRectifyMap(M2, D2, R2, P2, img_size, CV_16SC2, map21, map22);
Mat img1r, img2r;
remap(img1, img1r, map11, map12, INTER_LINEAR);
remap(img2, img2r, map21, map22, INTER_LINEAR);
img1 = img1r;
img2 = img2r;
}
numberOfDisparities = numberOfDisparities > 0 ? numberOfDisparities : ((img_size.width/8) + 15) & -16;
bm->setROI1(roi1);
bm->setROI2(roi2);
bm->setPreFilterCap(31);
bm->setBlockSize(SADWindowSize > 0 ? SADWindowSize : 9);
bm->setMinDisparity(0);
bm->setNumDisparities(numberOfDisparities);
bm->setTextureThreshold(10);
bm->setUniquenessRatio(15);
bm->setSpeckleWindowSize(100);
bm->setSpeckleRange(32);
bm->setDisp12MaxDiff(1);
sgbm->setPreFilterCap(63);
int sgbmWinSize = SADWindowSize > 0 ? SADWindowSize : 3;
sgbm->setBlockSize(sgbmWinSize);
int cn = img1.channels();
sgbm->setP1(8*cn*sgbmWinSize*sgbmWinSize);
sgbm->setP2(32*cn*sgbmWinSize*sgbmWinSize);
sgbm->setMinDisparity(0);
sgbm->setNumDisparities(numberOfDisparities);
sgbm->setUniquenessRatio(10);
sgbm->setSpeckleWindowSize(100);
sgbm->setSpeckleRange(32);
sgbm->setDisp12MaxDiff(1);
sgbm->setMode(alg == STEREO_HH ? StereoSGBM::MODE_HH : StereoSGBM::MODE_SGBM);
Mat disp, disp8;
int64 t = getTickCount();
if( alg == STEREO_BM )
bm->compute(img1, img2, disp);
else if( alg == STEREO_SGBM || alg == STEREO_HH )
sgbm->compute(img1, img2, disp);
t = getTickCount() - t;
printf("Time elapsed: %fms\n", t*1000/getTickFrequency());
if( alg != STEREO_VAR )
disp.convertTo(disp8, CV_8U, 255/(numberOfDisparities*16.));
else
disp.convertTo(disp8, CV_8U);
if( !no_display )
{
namedWindow("left", 1);
imshow("left", img1);
namedWindow("right", 1);
imshow("right", img2);
namedWindow("disparity", 0);
imshow("disparity", disp8);
printf("press any key to continue...");
fflush(stdout);
waitKey();
printf("\n");
}
if(disparity_filename)
imwrite(disparity_filename, disp8);
if(point_cloud_filename)
{
printf("storing the point cloud...");
fflush(stdout);
Mat xyz;
reprojectImageTo3D(disp, xyz, Q, true);
saveXYZ(point_cloud_filename, xyz);
printf("\n");
}
return 0;
}