opencv stereo vision depth map, code does not work - c++

Question

I am studying on stereo vision depth map and I am using the opencv library.I wrote a program to obtain depth map. But when program was run I obtained an empty depth map frame.can anybody help me please, what is wrong ? code are shown in below;
#include <opencv/highgui.h>
#include <opencv/cv.h>
#include <stdio.h>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <math.h>
#include <opencv2/calib3d/calib3d.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/contrib/contrib.hpp>
int main()
{
IplImage* img1 = cvLoadImage("/home/sezen/Masaüstü/imR.png");
IplImage* img2 = cvLoadImage("/home/sezen/Masaüstü/imL.png");
IplImage *rimage = cvCreateImage(
cvSize( img1->width, img1->height ), IPL_DEPTH_8U, 1 );
cvCvtColor( img1, rimage, CV_RGB2GRAY );
IplImage *limage = cvCreateImage(
cvSize( img2->width, img2->height ), IPL_DEPTH_8U, 1 );
cvCvtColor( img2, limage, CV_RGB2GRAY );
cvNamedWindow( "Right", CV_WINDOW_AUTOSIZE );
cvShowImage( "Right", rimage );
cvNamedWindow( "Left", CV_WINDOW_AUTOSIZE );
cvShowImage("Left", limage);
CvMat *matr = cvCreateMat(rimage->height,rimage->width,CV_8UC1 );
CvMat *matl = cvCreateMat(limage->height,limage->width,CV_8UC1 );
CvMat* disp = cvCreateMat(rimage->height,rimage->width,CV_16S);
CvMat* vdisp = cvCreateMat(rimage->height,rimage->width,CV_16S);
cvConvert( rimage, matr );
cvConvert( limage, matl );
CvStereoBMState *BMState = cvCreateStereoBMState();
assert(BMState != 0);
BMState->preFilterSize=21;
BMState->preFilterCap=31;
BMState->SADWindowSize=21;
BMState->minDisparity=0;
BMState->numberOfDisparities=128;
BMState->textureThreshold=10;
BMState->uniquenessRatio=15;
cvFindStereoCorrespondenceBM( matr, matl, disp, BMState);
cvNormalize(disp, vdisp, 0, 255, CV_MINMAX);
cvShowImage("depthmap", vdisp);
cvWaitKey(0);
return 0;
}

Answer 1

Here's a code for disparity map using C++ API. Final image that you normalize should be of type CV_8UC1.
Mat img1, img2, g1, g2;
Mat disp, disp8;
img1 = imread("leftImage.jpg");
img2 = imread("rightImage.jpg");
cvtColor(img1, g1, CV_BGR2GRAY);
cvtColor(img2, g2, CV_BGR2GRAY);
StereoBM sbm;
sbm.state->SADWindowSize = 9;
sbm.state->numberOfDisparities = 112;
sbm.state->preFilterSize = 5;
sbm.state->preFilterCap = 61;
sbm.state->minDisparity = -39;
sbm.state->textureThreshold = 507;
sbm.state->uniquenessRatio = 0;
sbm.state->speckleWindowSize = 0;
sbm.state->speckleRange = 8;
sbm.state->disp12MaxDiff = 1;
sbm(g1, g2, disp);
normalize(disp, disp8, 0, 255, CV_MINMAX, CV_8U);
imshow("left", img1);
imshow("right", img2);
imshow("disp", disp8);

Answer 2

I can only add that structure of OpenCV namespaces and classes changes every year.
I placed below working source code for OpenCV 3.4.0
#include <Windows.h>
#include <Vfw.h>
#include <string>
#include <iostream>
#include "opencv2\core\core.hpp"
#include "opencv2\imgproc\imgproc.hpp"
#include "opencv2\imgcodecs\imgcodecs.hpp"
#include "opencv2\highgui\highgui.hpp"
#include "opencv2\calib3d\calib3d.hpp"
using namespace std;
using namespace cv;
int _tmain(int argc, _TCHAR* argv[])
{
Mat im_left=imread("right.png");
Mat im_right=imread("left.png");
cv::Size imagesize = im_left.size();
cv::Mat disparity_left=cv::Mat(imagesize.height,imagesize.width,CV_16S);
cv::Mat disparity_right=cv::Mat(imagesize.height,imagesize.width,CV_16S);
cv::Mat g1,g2,disp,disp8;
cv::cvtColor(im_left,g1,cv::COLOR_BGR2GRAY);
cv::cvtColor(im_right,g2,cv::COLOR_BGR2GRAY);
cv::Ptr<cv::StereoBM> sbm = cv::StereoBM::create(0,21);
sbm->setDisp12MaxDiff(1);
sbm->setSpeckleRange(8);
sbm->setSpeckleWindowSize(9);
sbm->setUniquenessRatio(0);
sbm->setTextureThreshold(507);
sbm->setMinDisparity(-39);
sbm->setPreFilterCap(61);
sbm->setPreFilterSize(5);
sbm->compute(g1,g2,disparity_left);
normalize(disparity_left, disp8, 0, 255, CV_MINMAX, CV_8U);
cv::namedWindow("Left",CV_WINDOW_FREERATIO);
cv::imshow("Left", im_left);
cv::namedWindow("Right",CV_WINDOW_FREERATIO);
cv::imshow("Right", im_right);
cv::namedWindow("Depth map",CV_WINDOW_FREERATIO);
cv::imshow("Depth map", disp8);
cv::waitKey(0);
return 0;
}

Answer 3

For me it worked slightly different with the init of the stereoBM object
Ptr<StereoBM> sbm = cv::StereoBM::create(16, 5);
sbm->setDisp12MaxDiff(1);
sbm->setSpeckleRange(8);
sbm->setSpeckleWindowSize(0);
sbm->setUniquenessRatio(0);
sbm->setTextureThreshold(507);
sbm->setMinDisparity(-39);
sbm->setPreFilterCap(61);
sbm->setPreFilterSize(5);
sbm->compute(src1, src2, disp);

Answer 4

I edited the code to my needs, I added the camera one and two, and reading from them.
Then, made the Depth map. Thanks hope its helpful.
#include <string>
#include <iostream>
#include <opencv2/opencv.hpp>
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/imgcodecs/imgcodecs.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/calib3d/calib3d.hpp"
using namespace std;
using namespace cv;
int main()
{
VideoCapture leftCam(0); //lets say 0 is left, 1 is right
if (leftCam.isOpened() == false){cout << "error: Webcam connect unsuccessful\n"; return(0); }
VideoCapture rightCam(1); //lets say 0 is left, 1 is right
if (rightCam.isOpened() == false){cout << "error: Webcam connect unsuccessful\n"; return(0); }
Mat left, right;
Mat leftClone, rightClone;
char charCheckForEscKey = 0;
while ( charCheckForEscKey != 27 && leftCam.isOpened() )
{
leftCam.read(left);
if (left.empty()){cout << "No frame to read" << endl; break;}
leftClone = left.clone(); //copy from the left camera
imwrite("left.png", leftClone); // write it to screenshot.png in this directory
rightCam.read(right);
if (right.empty()){cout << "No frame to read" << endl; break;}
rightClone = right.clone(); //copy from the left camera
imwrite("right.png", rightClone); // write it to screenshot.png in this directory
Mat im_left = imread("left.png"); //left cam picture
Mat im_right = imread("right.png"); // right cam picture
Size imagesize = im_left.size();
Mat disparity_left= Mat(imagesize.height,imagesize.width,CV_16S);
Mat disparity_right=Mat(imagesize.height,imagesize.width,CV_16S);
Mat g1,g2,disp,disp8;
cvtColor(im_left,g1, COLOR_BGR2GRAY);
cvtColor(im_right,g2, COLOR_BGR2GRAY);
Ptr<cv::StereoBM> sbm = StereoBM::create(0,21);
sbm->setDisp12MaxDiff(1);
sbm->setSpeckleRange(8);
sbm->setSpeckleWindowSize(9);
sbm->setUniquenessRatio(0);
sbm->setTextureThreshold(507);
sbm->setMinDisparity(-39);
sbm->setPreFilterCap(61);
sbm->setPreFilterSize(5);
sbm->compute(g1,g2,disparity_left);
normalize(disparity_left, disp8, 0, 255, NORM_MINMAX, CV_8U);
namedWindow("Left", WINDOW_AUTOSIZE);
imshow("Left", im_left);
namedWindow("Right", WINDOW_AUTOSIZE);
imshow("Right", im_right);
namedWindow("Depth map", WINDOW_AUTOSIZE);
imshow("Depth map", disp8);
namedWindow("Left Cloned", WINDOW_FREERATIO);
imshow("Left Cloned", leftClone); // left is the left pic taken from camera 0
charCheckForEscKey = waitKey(1);
}
return(0);
}

Answer 5

#include <opencv2/opencv.hpp>
#include <opencv2/highgui.hpp>
#include<opencv2/calib3d.hpp>
int main()
{
cv::Mat leftimg =cv::imread("leftimage.jpg");
cv::Mat rightimg = cv::imread("rightimage.jpg");
cv::Mat disparity_left=cv::Mat(leftimg.size(),leftimg.type());
cv::Mat disparity_right=cv::Mat(rightimg.size(),rightimg .type());
cv::Mat g1,g2,disp,disp8;
cv::cvtColor(leftimg,g1,cv::COLOR_BGR2GRAY);
cv::cvtColor(rightimg,g2,cv::COLOR_BGR2GRAY);
cv::Ptr<cv::StereoBM> sbm = cv::createStereoBM(16,21);
sbm->setDisp12MaxDiff(1);
sbm->setSpeckleRange(8);
sbm->setSpeckleWindowSize(9);
sbm->setUniquenessRatio(0);
sbm->setTextureThreshold(507);
sbm->setMinDisparity(-39);
sbm->setPreFilterCap(61);
sbm->setPreFilterSize(5);
sbm->compute(g1,g2,disparity_left);
normalize(disparity_left, disp8, 0, 255, CV_MINMAX, CV_8U);
}