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Does the StereoBM class in opencv fix input images or frames?

I use the SteroBM class for stereo imaging as part of my project. I take input frames from 2 web cams and start the Stereoblock mapping based on gray frames of input frames without correction. The output that I get is far from the truth (very heterogeneous). I want to know, because I do not correct input frames. Moreover, the baseline that I chose is 20 cm long. I am using opencv-3.2.0 version of C ++.

The code I'm running is below.

#include <opencv2/core.hpp>
#include <opencv2/opencv.hpp>
#include </home/eswar/softwares/opencv_contrib-3.2.0/modules/contrib_world/include/opencv2/contrib_world.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/calib3d.hpp>
#include <opencv2/imgproc.hpp>
#include <stdio.h>
#include <iostream>

using namespace std;
using namespace cv;

int main()
{
 //initialize and allocate memory to load the video stream from camera 
 VideoCapture camera0(0);
 VideoCapture camera1(1);

 if( !camera0.isOpened() ) return 1;
 if( !camera1.isOpened() ) return 1;
 Mat frame0,frame1;
 Mat frame0gray,frame1gray;
 Mat dispbm,dispsgbm;
 Mat dispnorm_bm,dispnorm_sgbm;
 Mat falseColorsMap, sfalseColorsMap;
 int ndisparities = 16*5;   /**< Range of disparity */
 int SADWindowSize = 21; /**< Size of the block window. Must be odd */
 Ptr<StereoBM> sbm = StereoBM::create( ndisparities, SADWindowSize );
 Ptr<StereoSGBM> sgbm = StereoSGBM::create(0,    //int minDisparity
                                    96,     //int numDisparities
                                    5,      //int SADWindowSize
                                    600,    //int P1 = 0
                                    2400,   //int P2 = 0
                                    10,     //int disp12MaxDiff = 0
                                    16,     //int preFilterCap = 0
                                    2,      //int uniquenessRatio = 0
                                    20,    //int speckleWindowSize = 0
                                    30,     //int speckleRange = 0
                                    true);  //bool fullDP = false
//-- Check its extreme values
double minVal; double maxVal;
while(true) 
{
   //grab and retrieve each frames of the video sequentially 
   camera0 >> frame0;
   camera1 >> frame1;

   imshow("Video0", frame0);
   imshow("Video1", frame1);
   cvtColor(frame0,frame0gray,CV_BGR2GRAY);
   cvtColor(frame1,frame1gray,CV_BGR2GRAY);

   sbm->compute( frame0gray, frame1gray, dispbm );
   minMaxLoc( dispbm, &minVal, &maxVal );
   dispbm.convertTo( dispnorm_bm, CV_8UC1, 255/(maxVal - minVal));

   sgbm->compute(frame0gray, frame1gray, dispsgbm);
   minMaxLoc( dispsgbm, &minVal, &maxVal );
   dispsgbm.convertTo( dispnorm_sgbm, CV_8UC1, 255/(maxVal - minVal));

   imshow( "BM", dispnorm_bm);
   imshow( "SGBM",dispnorm_sgbm);

   //wait for 40 milliseconds
   int c = cvWaitKey(40);
   //exit the loop if user press "Esc" key  (ASCII value of "Esc" is 27) 
   if(27 == char(c)) break;
 }
 return 0;
}

, , , , . , SGBM , . - , . , , , .

SGBM. Depth map using the SGBM method

+4
2

, . .

#include <opencv2/core.hpp>
#include <opencv2/opencv.hpp>
#include </home/eswar/softwares/opencv_contrib-3.2.0/modules/contrib_world  /include/opencv2/contrib_world.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/calib3d.hpp>
#include <opencv2/imgproc.hpp>
#include <stdio.h>
#include <iostream>
#include <opencv2/xfeatures2d/nonfree.hpp>

using namespace std;
using namespace cv;
using namespace cv::xfeatures2d;

int main()
{
//initialize and allocate memory to load the video stream from camera 
VideoCapture camera0(0);
VideoCapture camera1(1);
int count=0;
Mat loRes, hiRes;
if( !camera0.isOpened() ) return 1;
if( !camera1.isOpened() ) return 1;
camera0.set(CV_CAP_PROP_FRAME_WIDTH, 400);
camera0.set(CV_CAP_PROP_FRAME_HEIGHT, 400); 
camera1.set(CV_CAP_PROP_FRAME_WIDTH, 400);
camera1.set(CV_CAP_PROP_FRAME_HEIGHT, 400);
Mat frame0,frame1;
Mat frame0gray,frame1gray;
Mat dispbm,dispsgbm,disparity,disparity1;
Mat dispnorm_bm,dispnorm_sgbm;
Mat falseColorsMap, sfalseColorsMap,falsemap;
Mat img_matches;
Mat H1,H2;

int ndisparities = 96;   /**< Range of disparity */
int SADWindowSize = 7;
Ptr<StereoBM> sbm = StereoBM::create( ndisparities, SADWindowSize );

Ptr<StereoSGBM> sgbm = StereoSGBM::create(-3,    //int minDisparity
                                    96,     //int numDisparities
                                    7,      //int SADWindowSize
                                    60,    //int P1 = 0
                                    2400,   //int P2 = 0
                                    90,     //int disp12MaxDiff = 0
                                    16,     //int preFilterCap = 0
                                    1,      //int uniquenessRatio = 0
                                    60,    //int speckleWindowSize = 0
                                    20,     //int speckleRange = 0
                                    true);  //bool fullDP = false


 //-- Check its extreme values
 double minVal; double maxVal;
 double max_dist = 0;
 double min_dist = 100;
 int minHessian = 630;
 Ptr<Feature2D> f2d = SIFT::create();
 vector<KeyPoint> keypoints_1, keypoints_2;
 Ptr<Feature2D> fd = SIFT::create();
 Mat descriptors_1, descriptors_2;
 BFMatcher matcher(NORM_L2, true);   //BFMatcher matcher(NORM_L2);
 vector< DMatch > matches;
 vector< DMatch > good_matches;
 vector<Point2f>imgpts1,imgpts2;
 vector<uchar> status;
while(true) 
{
    //grab and retrieve each frames of the video sequentially 
    camera0 >> frame0;
    camera1 >> frame1;
    imshow("Video0", frame0);
    imshow("Video1", frame1);

    cvtColor(frame0,frame0gray,CV_BGR2GRAY);
    cvtColor(frame1,frame1gray,CV_BGR2GRAY); 

    sbm->compute( frame0gray, frame1gray, dispbm );
    minMaxLoc( dispbm, &minVal, &maxVal );
    dispbm.convertTo( dispnorm_bm, CV_8UC1, 255/(maxVal - minVal));

    sgbm->compute(frame0gray, frame1gray, dispsgbm);
    minMaxLoc( dispsgbm, &minVal, &maxVal );
    dispsgbm.convertTo( dispnorm_sgbm, CV_8UC1, 255/(maxVal - minVal));
    applyColorMap(dispnorm_bm, falseColorsMap, cv::COLORMAP_JET);
    applyColorMap(dispnorm_sgbm, sfalseColorsMap, cv::COLORMAP_JET);

    f2d->detect( frame0gray, keypoints_1 );
    f2d->detect( frame1gray, keypoints_2 );

    //-- Step 2: Calculate descriptors (feature vectors)
    fd->compute( frame0gray, keypoints_1, descriptors_1 );
    fd->compute( frame1gray, keypoints_2, descriptors_2 );

    //-- Step 3: Matching descriptor vectors with a brute force matcher

    matcher.match( descriptors_1, descriptors_2, matches );
    drawMatches(frame0gray, keypoints_1, frame1gray, keypoints_2, matches, img_matches);
    imshow("matches", img_matches);

    //-- Quick calculation of max and min distances between keypoints
    for( int i = 0; i < matches.size(); i++ )
    { double dist = matches[i].distance;
      if( dist < min_dist ) min_dist = dist;
      if( dist > max_dist ) max_dist = dist;
    } 

   for( int i = 0; i < matches.size(); i++ )
   {
     if( matches[i].distance <= max(4.5*min_dist, 0.02) ){
         good_matches.push_back( matches[i]);
         imgpts1.push_back(keypoints_1[matches[i].queryIdx].pt);
         imgpts2.push_back(keypoints_2[matches[i].trainIdx].pt);
      }

   }

   Mat F = findFundamentalMat(imgpts1, imgpts2, cv::FM_RANSAC, 3., 0.99, status);   //FM_RANSAC
   stereoRectifyUncalibrated(imgpts1, imgpts1, F, frame0gray.size(), H1, H2);
   Mat rectified1(frame0gray.size(), frame0gray.type());
   warpPerspective(frame0gray, rectified1, H1, frame0gray.size());

   Mat rectified2(frame1gray.size(), frame1gray.type());
   warpPerspective(frame1gray, rectified2, H2, frame1gray.size());

   sgbm->compute(rectified1, rectified2, disparity);
   minMaxLoc( disparity, &minVal, &maxVal );
   disparity.convertTo( disparity1, CV_8UC1, 255/(maxVal - minVal));
   applyColorMap(disparity1, falsemap, cv::COLORMAP_JET);
   imshow("disparity_rectified_color", falsemap);
   imshow( "BM", falseColorsMap);
   imshow( "CSGBM",sfalseColorsMap);

   //wait for 40 milliseconds
    int c = cvWaitKey(40);

    //exit the loop if user press "Esc" key  (ASCII value of "Esc" is 27) 
    if(27 == char(c)) break;
}

return 0;

}

, . , , , . . . ? .

+3

, StereoBM , -, opencv

opencv, .

StereoBM SAD ( ), , wls filter, .

StereoSGBM SGM ( , ), , , , .

+2

Source: https://habr.com/ru/post/1684352/

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