boarddetector.cpp

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/*****************************
Copyright 2011 Rafael Muñoz Salinas. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are
permitted provided that the following conditions are met:

   1. Redistributions of source code must retain the above copyright notice, this list of
      conditions and the following disclaimer.

   2. Redistributions in binary form must reproduce the above copyright notice, this list
      of conditions and the following disclaimer in the documentation and/or other materials
      provided with the distribution.

THIS SOFTWARE IS PROVIDED BY Rafael Muñoz Salinas ''AS IS'' AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL Rafael Muñoz Salinas OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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The views and conclusions contained in the software and documentation are those of the
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or implied, of Rafael Muñoz Salinas.
********************************/
#include "boarddetector.h"
#define _USE_MATH_DEFINES
#include <math.h>
#include <cstdlib>
#include <ctime>
#include <cassert>
#include <fstream>
#include <opencv2/calib3d/calib3d.hpp>
using namespace std;
using namespace cv;
namespace aruco {
BoardDetector::BoardDetector(bool setYPerpendicular) {
    _setYPerpendicular = setYPerpendicular;
    _areParamsSet = false;
    repj_err_thres = -1;
}
void BoardDetector::setParams(const BoardConfiguration &bc, const CameraParameters &cp, float markerSizeMeters) {
    _camParams = cp;
    _markerSize = markerSizeMeters;
    _bconf = bc;
    _areParamsSet = true;
}
void BoardDetector::setParams(const BoardConfiguration &bc) {
    _bconf = bc;
    _areParamsSet = true;
}

float BoardDetector::detect(const cv::Mat &im) throw(cv::Exception) {
    _mdetector.detect(im, _vmarkers);

    float res;

    if (_camParams.isValid())
        res = detect(_vmarkers, _bconf, _boardDetected, _camParams.CameraMatrix, _camParams.Distorsion, _markerSize);
    else
        res = detect(_vmarkers, _bconf, _boardDetected);
    return res;
}
float BoardDetector::detect(const vector< Marker > &detectedMarkers, const BoardConfiguration &BConf, Board &Bdetected, const CameraParameters &cp,
                            float markerSizeMeters) throw(cv::Exception) {
    return detect(detectedMarkers, BConf, Bdetected, cp.CameraMatrix, cp.Distorsion, markerSizeMeters);
}
float BoardDetector::detect(const vector< Marker > &detectedMarkers, const BoardConfiguration &BConf, Board &Bdetected, Mat camMatrix, Mat distCoeff,
                            float markerSizeMeters) throw(cv::Exception) {
    if (BConf.size() == 0)
        throw cv::Exception(8881, "BoardDetector::detect", "Invalid BoardConfig that is empty", __FILE__, __LINE__);
    if (BConf[0].size() < 2)
        throw cv::Exception(8881, "BoardDetector::detect", "Invalid BoardConfig that is empty 2", __FILE__, __LINE__);
    // compute the size of the markers in meters, which is used for some routines(mostly drawing)
    float ssize;
    if (BConf.mInfoType == BoardConfiguration::PIX && markerSizeMeters > 0)
        ssize = markerSizeMeters;
    else if (BConf.mInfoType == BoardConfiguration::METERS) {
        ssize = cv::norm(BConf[0][0] - BConf[0][1]);
    }

    // cout<<"markerSizeMeters="<<markerSizeMeters<<endl;
    Bdetected.clear();
    for (unsigned int i = 0; i < detectedMarkers.size(); i++) {
        int idx = BConf.getIndexOfMarkerId(detectedMarkers[i].id);
        if (idx != -1) {
            Bdetected.push_back(detectedMarkers[i]);
            Bdetected.back().ssize = ssize;
        }
    }
    // copy configuration
    Bdetected.conf = BConf;
    //

    bool hasEnoughInfoForRTvecCalculation = false;
    if (Bdetected.size() >= 1) {
        if (camMatrix.rows != 0) {
            if (markerSizeMeters > 0 && BConf.mInfoType == BoardConfiguration::PIX)
                hasEnoughInfoForRTvecCalculation = true;
            else if (BConf.mInfoType == BoardConfiguration::METERS)
                hasEnoughInfoForRTvecCalculation = true;
        }
    }

    // calculate extrinsic if there is information for that
    if (hasEnoughInfoForRTvecCalculation) {

        // calculate the size of the markers in meters if expressed in pixels
        double marker_meter_per_pix = 0;
        if (BConf.mInfoType == BoardConfiguration::PIX)
            marker_meter_per_pix = markerSizeMeters / cv::norm(BConf[0][0] - BConf[0][1]);
        else
            marker_meter_per_pix = 1; // to avoind interferring the process below

        // now, create the matrices for finding the extrinsics
        vector< cv::Point3f > objPoints;
        vector< cv::Point2f > imagePoints;
        for (size_t i = 0; i < Bdetected.size(); i++) {
            int idx = Bdetected.conf.getIndexOfMarkerId(Bdetected[i].id);
            assert(idx != -1);
            for (int p = 0; p < 4; p++) {
                imagePoints.push_back(Bdetected[i][p]);
                const aruco::MarkerInfo &Minfo = Bdetected.conf.getMarkerInfo(Bdetected[i].id);
                objPoints.push_back(Minfo[p] * marker_meter_per_pix);
                //              cout<<objPoints.back()<<endl;
            }
        }
        if (distCoeff.total() == 0)
            distCoeff = cv::Mat::zeros(1, 4, CV_32FC1);

        //          for(size_t i=0;i< imagePoints.size();i++){
        //              cout<<objPoints[i]<<" "<<imagePoints[i]<<endl;
        //          }
        //          cout<<"cam="<<camMatrix<<" "<<distCoeff<<endl;
        cv::Mat rvec, tvec;
        cv::solvePnP(objPoints, imagePoints, camMatrix, distCoeff, rvec, tvec);
        rvec.convertTo(Bdetected.Rvec, CV_32FC1);
        tvec.convertTo(Bdetected.Tvec, CV_32FC1);
        //             cout<<rvec<< " "<<tvec<<" _setYPerpendicular="<<_setYPerpendicular<<endl;

        {
            vector< cv::Point2f > reprojected;
            cv::projectPoints(objPoints, rvec, tvec, camMatrix, distCoeff, reprojected);
            double errSum = 0;
            // check now the reprojection error and
            for (size_t i = 0; i < reprojected.size(); i++) {
                errSum += cv::norm(reprojected[i] - imagePoints[i]);
            }
            //                  cout<<"AAA RE="<<errSum/double ( reprojected.size() ) <<endl;
        }
        // now, do a refinement and remove points whose reprojection error is above a threshold, then repeat calculation with the rest
        if (repj_err_thres > 0) {
            vector< cv::Point2f > reprojected;
            cv::projectPoints(objPoints, rvec, tvec, camMatrix, distCoeff, reprojected);

            vector< int > pointsThatPassTest; // indices
            // check now the reprojection error and
            for (size_t i = 0; i < reprojected.size(); i++) {
                float err = cv::norm(reprojected[i] - imagePoints[i]);
                if (err < repj_err_thres)
                    pointsThatPassTest.push_back(i);
            }
            // cerr<<"Number of points after reprjection test "<<pointsThatPassTest.size() <<"/"<<objPoints.size() <<endl;
            // copy these data to another vectors and repeat
            vector< cv::Point3f > objPoints_filtered;
            vector< cv::Point2f > imagePoints_filtered;
            for (size_t i = 0; i < pointsThatPassTest.size(); i++) {
                objPoints_filtered.push_back(objPoints[pointsThatPassTest[i]]);
                imagePoints_filtered.push_back(imagePoints[pointsThatPassTest[i]]);
            }

            cv::solvePnP(objPoints_filtered, imagePoints_filtered, camMatrix, distCoeff, rvec, tvec);
            rvec.convertTo(Bdetected.Rvec, CV_32FC1);
            tvec.convertTo(Bdetected.Tvec, CV_32FC1);
        }


        // now, rotate 90 deg in X so that Y axis points up
        if (_setYPerpendicular)
            rotateXAxis(Bdetected.Rvec);
        //         cout<<Bdetected.Rvec.at<float>(0,0)<<" "<<Bdetected.Rvec.at<float>(1,0)<<" "<<Bdetected.Rvec.at<float>(2,0)<<endl;
        //         cout<<Bdetected.Tvec.at<float>(0,0)<<" "<<Bdetected.Tvec.at<float>(1,0)<<" "<<Bdetected.Tvec.at<float>(2,0)<<endl;
    }

    float prob = float(Bdetected.size()) / double(Bdetected.conf.size());
    return prob;
}

void BoardDetector::rotateXAxis(Mat &rotation) {
    cv::Mat R(3, 3, CV_32FC1);
    Rodrigues(rotation, R);
    // create a rotation matrix for x axis
    cv::Mat RX = cv::Mat::eye(3, 3, CV_32FC1);
    float angleRad = -M_PI / 2;
    RX.at< float >(1, 1) = cos(angleRad);
    RX.at< float >(1, 2) = -sin(angleRad);
    RX.at< float >(2, 1) = sin(angleRad);
    RX.at< float >(2, 2) = cos(angleRad);
    // now multiply
    R = R * RX;
    // finally, the the rodrigues back
    Rodrigues(R, rotation);
}

Board BoardDetector::detect(const cv::Mat &Image, const BoardConfiguration &bc, const CameraParameters &cp, float markerSizeMeters) {
    BoardDetector BD;
    BD.setParams(bc, cp, markerSizeMeters);
    BD.detect(Image);
    return BD.getDetectedBoard();
}
};