390 lines
14 KiB
C++
390 lines
14 KiB
C++
/* This is sample from the OpenCV book. The copyright notice is below */
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/* *************** License:**************************
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Oct. 3, 2008
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Right to use this code in any way you want without warrenty, support or any guarentee of it working.
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BOOK: It would be nice if you cited it:
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Learning OpenCV: Computer Vision with the OpenCV Library
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by Gary Bradski and Adrian Kaehler
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Published by O'Reilly Media, October 3, 2008
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AVAILABLE AT:
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http://www.amazon.com/Learning-OpenCV-Computer-Vision-Library/dp/0596516134
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Or: http://oreilly.com/catalog/9780596516130/
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ISBN-10: 0596516134 or: ISBN-13: 978-0596516130
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OTHER OPENCV SITES:
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* The source code is on sourceforge at:
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http://sourceforge.net/projects/opencvlibrary/
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* The OpenCV wiki page (As of Oct 1, 2008 this is down for changing over servers, but should come back):
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http://opencvlibrary.sourceforge.net/
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* An active user group is at:
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http://tech.groups.yahoo.com/group/OpenCV/
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* The minutes of weekly OpenCV development meetings are at:
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http://pr.willowgarage.com/wiki/OpenCV
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************************************************** */
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#undef _GLIBCXX_DEBUG
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#include "cv.h"
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#include "cxmisc.h"
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#include "highgui.h"
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#include <vector>
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#include <string>
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#include <algorithm>
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#include <stdio.h>
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#include <ctype.h>
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using namespace std;
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//
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// Given a list of chessboard images, the number of corners (nx, ny)
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// on the chessboards, and a flag: useCalibrated for calibrated (0) or
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// uncalibrated (1: use cvStereoCalibrate(), 2: compute fundamental
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// matrix separately) stereo. Calibrate the cameras and display the
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// rectified results along with the computed disparity images.
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//
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static void
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StereoCalib(const char* path, const char* imageList, int useUncalibrated)
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{
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CvRect roi1, roi2;
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int nx = 0, ny = 0;
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int displayCorners = 1;
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int showUndistorted = 1;
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bool isVerticalStereo = false;//OpenCV can handle left-right
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//or up-down camera arrangements
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const int maxScale = 1;
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const float squareSize = 1.f; //Set this to your actual square size
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FILE* f = fopen(imageList, "rt");
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int i, j, lr, nframes = 0, n, N = 0;
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vector<string> imageNames[2];
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vector<CvPoint3D32f> objectPoints;
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vector<CvPoint2D32f> points[2];
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vector<CvPoint2D32f> temp_points[2];
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vector<int> npoints;
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// vector<uchar> active[2];
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int is_found[2] = {0, 0};
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vector<CvPoint2D32f> temp;
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CvSize imageSize = {0,0};
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// ARRAY AND VECTOR STORAGE:
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double M1[3][3], M2[3][3], D1[5], D2[5];
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double R[3][3], T[3], E[3][3], F[3][3];
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double Q[4][4];
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CvMat _M1 = cvMat(3, 3, CV_64F, M1 );
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CvMat _M2 = cvMat(3, 3, CV_64F, M2 );
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CvMat _D1 = cvMat(1, 5, CV_64F, D1 );
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CvMat _D2 = cvMat(1, 5, CV_64F, D2 );
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CvMat matR = cvMat(3, 3, CV_64F, R );
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CvMat matT = cvMat(3, 1, CV_64F, T );
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CvMat matE = cvMat(3, 3, CV_64F, E );
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CvMat matF = cvMat(3, 3, CV_64F, F );
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CvMat matQ = cvMat(4, 4, CV_64FC1, Q);
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char buf[1024];
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if( displayCorners )
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cvNamedWindow( "corners", 1 );
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// READ IN THE LIST OF CHESSBOARDS:
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if( !f )
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{
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fprintf(stderr, "can not open file %s\n", imageList );
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return;
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}
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if( !fgets(buf, sizeof(buf)-3, f) || sscanf(buf, "%d%d", &nx, &ny) != 2 )
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return;
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n = nx*ny;
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temp.resize(n);
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temp_points[0].resize(n);
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temp_points[1].resize(n);
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for(i=0;;i++)
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{
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int count = 0, result=0;
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lr = i % 2;
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vector<CvPoint2D32f>& pts = temp_points[lr];//points[lr];
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if( !fgets( buf, sizeof(buf)-3, f ))
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break;
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size_t len = strlen(buf);
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while( len > 0 && isspace(buf[len-1]))
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buf[--len] = '\0';
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if( buf[0] == '#')
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continue;
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char fullpath[1024];
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sprintf(fullpath, "%s/%s", path, buf);
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IplImage* img = cvLoadImage( fullpath, 0 );
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if( !img )
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{
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printf("Cannot read file %s\n", fullpath);
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return;
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}
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imageSize = cvGetSize(img);
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imageNames[lr].push_back(buf);
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//FIND CHESSBOARDS AND CORNERS THEREIN:
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for( int s = 1; s <= maxScale; s++ )
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{
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IplImage* timg = img;
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if( s > 1 )
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{
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timg = cvCreateImage(cvSize(img->width*s,img->height*s),
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img->depth, img->nChannels );
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cvResize( img, timg, CV_INTER_CUBIC );
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}
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result = cvFindChessboardCorners( timg, cvSize(nx, ny),
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&temp[0], &count,
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CV_CALIB_CB_ADAPTIVE_THRESH |
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CV_CALIB_CB_NORMALIZE_IMAGE);
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if( timg != img )
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cvReleaseImage( &timg );
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if( result || s == maxScale )
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for( j = 0; j < count; j++ )
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{
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temp[j].x /= s;
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temp[j].y /= s;
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}
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if( result )
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break;
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}
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if( displayCorners )
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{
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printf("%s\n", buf);
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IplImage* cimg = cvCreateImage( imageSize, 8, 3 );
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cvCvtColor( img, cimg, CV_GRAY2BGR );
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cvDrawChessboardCorners( cimg, cvSize(nx, ny), &temp[0],
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count, result );
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IplImage* cimg1 = cvCreateImage(cvSize(640, 480), IPL_DEPTH_8U, 3);
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cvResize(cimg, cimg1);
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cvShowImage( "corners", cimg1 );
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cvReleaseImage( &cimg );
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cvReleaseImage( &cimg1 );
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int c = cvWaitKey(1000);
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if( c == 27 || c == 'q' || c == 'Q' ) //Allow ESC to quit
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exit(-1);
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}
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else
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putchar('.');
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//N = pts.size();
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//pts.resize(N + n, cvPoint2D32f(0,0));
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//active[lr].push_back((uchar)result);
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is_found[lr] = result > 0 ? 1 : 0;
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//assert( result != 0 );
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if( result )
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{
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//Calibration will suffer without subpixel interpolation
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cvFindCornerSubPix( img, &temp[0], count,
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cvSize(11, 11), cvSize(-1,-1),
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cvTermCriteria(CV_TERMCRIT_ITER+CV_TERMCRIT_EPS,
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30, 0.01) );
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copy( temp.begin(), temp.end(), pts.begin() );
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}
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cvReleaseImage( &img );
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if(lr)
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{
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if(is_found[0] == 1 && is_found[1] == 1)
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{
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assert(temp_points[0].size() == temp_points[1].size());
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int current_size = points[0].size();
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points[0].resize(current_size + temp_points[0].size(), cvPoint2D32f(0.0, 0.0));
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points[1].resize(current_size + temp_points[1].size(), cvPoint2D32f(0.0, 0.0));
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copy(temp_points[0].begin(), temp_points[0].end(), points[0].begin() + current_size);
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copy(temp_points[1].begin(), temp_points[1].end(), points[1].begin() + current_size);
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nframes++;
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printf("Pair successfully detected...\n");
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}
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is_found[0] = 0;
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is_found[1] = 0;
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}
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}
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fclose(f);
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printf("\n");
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// HARVEST CHESSBOARD 3D OBJECT POINT LIST:
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objectPoints.resize(nframes*n);
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for( i = 0; i < ny; i++ )
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for( j = 0; j < nx; j++ )
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objectPoints[i*nx + j] =
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cvPoint3D32f(i*squareSize, j*squareSize, 0);
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for( i = 1; i < nframes; i++ )
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copy( objectPoints.begin(), objectPoints.begin() + n,
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objectPoints.begin() + i*n );
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npoints.resize(nframes,n);
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N = nframes*n;
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CvMat _objectPoints = cvMat(1, N, CV_32FC3, &objectPoints[0] );
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CvMat _imagePoints1 = cvMat(1, N, CV_32FC2, &points[0][0] );
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CvMat _imagePoints2 = cvMat(1, N, CV_32FC2, &points[1][0] );
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CvMat _npoints = cvMat(1, npoints.size(), CV_32S, &npoints[0] );
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cvSetIdentity(&_M1);
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cvSetIdentity(&_M2);
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cvZero(&_D1);
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cvZero(&_D2);
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// CALIBRATE THE STEREO CAMERAS
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printf("Running stereo calibration ...");
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fflush(stdout);
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cvStereoCalibrate( &_objectPoints, &_imagePoints1,
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&_imagePoints2, &_npoints,
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&_M1, &_D1, &_M2, &_D2,
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imageSize, &matR, &matT, &matE, &matF,
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cvTermCriteria(CV_TERMCRIT_ITER+
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CV_TERMCRIT_EPS, 100, 1e-5),
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CV_CALIB_FIX_ASPECT_RATIO +
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CV_CALIB_ZERO_TANGENT_DIST +
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CV_CALIB_SAME_FOCAL_LENGTH +
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CV_CALIB_FIX_K3);
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printf(" done\n");
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// CALIBRATION QUALITY CHECK
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// because the output fundamental matrix implicitly
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// includes all the output information,
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// we can check the quality of calibration using the
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// epipolar geometry constraint: m2^t*F*m1=0
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vector<CvPoint3D32f> lines[2];
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points[0].resize(N);
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points[1].resize(N);
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_imagePoints1 = cvMat(1, N, CV_32FC2, &points[0][0] );
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_imagePoints2 = cvMat(1, N, CV_32FC2, &points[1][0] );
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lines[0].resize(N);
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lines[1].resize(N);
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CvMat _L1 = cvMat(1, N, CV_32FC3, &lines[0][0]);
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CvMat _L2 = cvMat(1, N, CV_32FC3, &lines[1][0]);
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//Always work in undistorted space
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cvUndistortPoints( &_imagePoints1, &_imagePoints1,
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&_M1, &_D1, 0, &_M1 );
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cvUndistortPoints( &_imagePoints2, &_imagePoints2,
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&_M2, &_D2, 0, &_M2 );
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cvComputeCorrespondEpilines( &_imagePoints1, 1, &matF, &_L1 );
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cvComputeCorrespondEpilines( &_imagePoints2, 2, &matF, &_L2 );
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double avgErr = 0;
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for( i = 0; i < N; i++ )
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{
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double err = fabs(points[0][i].x*lines[1][i].x +
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points[0][i].y*lines[1][i].y + lines[1][i].z)
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+ fabs(points[1][i].x*lines[0][i].x +
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points[1][i].y*lines[0][i].y + lines[0][i].z);
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avgErr += err;
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}
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printf( "avg err = %g\n", avgErr/(nframes*n) );
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// save intrinsic parameters
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CvFileStorage* fstorage = cvOpenFileStorage("intrinsics.yml", NULL, CV_STORAGE_WRITE);
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cvWrite(fstorage, "M1", &_M1);
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cvWrite(fstorage, "D1", &_D1);
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cvWrite(fstorage, "M2", &_M2);
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cvWrite(fstorage, "D2", &_D2);
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cvReleaseFileStorage(&fstorage);
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//COMPUTE AND DISPLAY RECTIFICATION
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if( showUndistorted )
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{
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CvMat* mx1 = cvCreateMat( imageSize.height,
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imageSize.width, CV_32F );
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CvMat* my1 = cvCreateMat( imageSize.height,
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imageSize.width, CV_32F );
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CvMat* mx2 = cvCreateMat( imageSize.height,
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imageSize.width, CV_32F );
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CvMat* my2 = cvCreateMat( imageSize.height,
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imageSize.width, CV_32F );
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CvMat* img1r = cvCreateMat( imageSize.height,
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imageSize.width, CV_8U );
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CvMat* img2r = cvCreateMat( imageSize.height,
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imageSize.width, CV_8U );
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CvMat* disp = cvCreateMat( imageSize.height,
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imageSize.width, CV_16S );
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double R1[3][3], R2[3][3], P1[3][4], P2[3][4];
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CvMat _R1 = cvMat(3, 3, CV_64F, R1);
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CvMat _R2 = cvMat(3, 3, CV_64F, R2);
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// IF BY CALIBRATED (BOUGUET'S METHOD)
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if( useUncalibrated == 0 )
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{
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CvMat _P1 = cvMat(3, 4, CV_64F, P1);
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CvMat _P2 = cvMat(3, 4, CV_64F, P2);
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cvStereoRectify( &_M1, &_M2, &_D1, &_D2, imageSize,
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&matR, &matT,
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&_R1, &_R2, &_P1, &_P2, &matQ,
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CV_CALIB_ZERO_DISPARITY,
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1, imageSize, &roi1, &roi2);
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CvFileStorage* file = cvOpenFileStorage("extrinsics.yml", NULL, CV_STORAGE_WRITE);
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cvWrite(file, "R", &matR);
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cvWrite(file, "T", &matT);
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cvWrite(file, "R1", &_R1);
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cvWrite(file, "R2", &_R2);
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cvWrite(file, "P1", &_P1);
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cvWrite(file, "P2", &_P2);
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cvWrite(file, "Q", &matQ);
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cvReleaseFileStorage(&file);
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isVerticalStereo = fabs(P2[1][3]) > fabs(P2[0][3]);
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if(!isVerticalStereo)
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roi2.x += imageSize.width;
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else
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roi2.y += imageSize.height;
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//Precompute maps for cvRemap()
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cvInitUndistortRectifyMap(&_M1,&_D1,&_R1,&_P1,mx1,my1);
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cvInitUndistortRectifyMap(&_M2,&_D2,&_R2,&_P2,mx2,my2);
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}
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//OR ELSE HARTLEY'S METHOD
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else if( useUncalibrated == 1 || useUncalibrated == 2 )
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// use intrinsic parameters of each camera, but
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// compute the rectification transformation directly
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// from the fundamental matrix
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{
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double H1[3][3], H2[3][3], iM[3][3];
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CvMat _H1 = cvMat(3, 3, CV_64F, H1);
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CvMat _H2 = cvMat(3, 3, CV_64F, H2);
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CvMat _iM = cvMat(3, 3, CV_64F, iM);
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//Just to show you could have independently used F
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if( useUncalibrated == 2 )
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cvFindFundamentalMat( &_imagePoints1,
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&_imagePoints2, &matF);
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cvStereoRectifyUncalibrated( &_imagePoints1,
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&_imagePoints2, &matF,
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imageSize,
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&_H1, &_H2, 3);
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cvInvert(&_M1, &_iM);
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cvMatMul(&_H1, &_M1, &_R1);
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cvMatMul(&_iM, &_R1, &_R1);
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cvInvert(&_M2, &_iM);
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cvMatMul(&_H2, &_M2, &_R2);
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cvMatMul(&_iM, &_R2, &_R2);
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//Precompute map for cvRemap()
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cvInitUndistortRectifyMap(&_M1,&_D1,&_R1,&_M1,mx1,my1);
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cvInitUndistortRectifyMap(&_M2,&_D1,&_R2,&_M2,mx2,my2);
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}
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else
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assert(0);
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cvReleaseMat( &mx1 );
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cvReleaseMat( &my1 );
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cvReleaseMat( &mx2 );
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cvReleaseMat( &my2 );
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cvReleaseMat( &img1r );
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cvReleaseMat( &img2r );
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cvReleaseMat( &disp );
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}
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}
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int main(int argc, char** argv)
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{
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if(argc > 1 && !strcmp(argv[1], "--help"))
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{
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printf("Usage:\n ./stereo_calib <path to images> <file wtih image list>\n");
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return 0;
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}
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StereoCalib(argc > 1 ? argv[1] : ".", argc > 2 ? argv[2] : "stereo_calib.txt", 0);
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return 0;
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}
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