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/*------------------------------------------------------------------------------------------*\

   This file contains material supporting chapter 9 of the cookbook:  

   Computer Vision Programming using the OpenCV Library.

   by Robert Laganiere, Packt Publishing, 2011.

   This program is free software; permission is hereby granted to use, copy, modify,

   and distribute this source code, or portions thereof, for any purpose, without fee,

   subject to the restriction that the copyright notice may not be removed

   or altered from any source or altered source distribution.

   The software is released on an as-is basis and without any warranties of any kind.

   In particular, the software is not guaranteed to be fault-tolerant or free from failure.

   The author disclaims all warranties with regard to this software, any use,

   and any consequent failure, is purely the responsibility of the user.

   Copyright (C) 2010-2011 Robert Laganiere, www.laganiere.name

\*------------------------------------------------------------------------------------------*/

#include "CameraCalibrator.h"

// Open chessboard images and extract corner points

int CameraCalibrator::addChessboardPoints(

         const std::vector<std::string>& filelist,

         cv::Size & boardSize) {

        // the points on the chessboard

    std::vector<cv::Point2f> imageCorners;

    std::vector<cv::Point3f> objectCorners;

    // 3D Scene Points:

    // Initialize the chessboard corners 

    // in the chessboard reference frame

        // The corners are at 3D location (X,Y,Z)= (i,j,0)

        for (int i=0; i<boardSize.height; i++) {

                for (int j=0; j<boardSize.width; j++) {

                        objectCorners.push_back(cv::Point3f(i, j, 0.0f));

                }

    }

    // 2D Image points:

    cv::Mat image; // to contain chessboard image

    int successes = 0;

    // for all viewpoints

    for (int i=0; i<filelist.size(); i++) {

        // Open the image

        image = cv::imread(filelist[i],0);

        // Get the chessboard corners

        bool found = cv::findChessboardCorners(

                        image, boardSize, imageCorners);

        // Get subpixel accuracy on the corners

        cv::cornerSubPix(image, imageCorners,

                  cv::Size(5,5),

                  cv::Size(-1,-1),

                        cv::TermCriteria(cv::TermCriteria::MAX_ITER +

                          cv::TermCriteria::EPS,

             30,                // max number of iterations 

             0.1));     // min accuracy

          // If we have a good board, add it to our data

                  if (imageCorners.size() == boardSize.area()) {

                        // Add image and scene points from one view

            addPoints(imageCorners, objectCorners);

            successes++;

          }

        //Draw the corners

        cv::drawChessboardCorners(image, boardSize, imageCorners, found);

        cv::imshow("Corners on Chessboard", image);

        cv::waitKey(100);

    }

        return successes;

}

// Add scene points and corresponding image points

void CameraCalibrator::addPoints(const std::vector<cv::Point2f>& imageCorners, const std::vector<cv::Point3f>& objectCorners) {

        // 2D image points from one view

        imagePoints.push_back(imageCorners);          

        // corresponding 3D scene points

        objectPoints.push_back(objectCorners);

}

// Calibrate the camera

// returns the re-projection error

double CameraCalibrator::calibrate(cv::Size &imageSize)

{

        // undistorter must be reinitialized

        mustInitUndistort= true;

        //Output rotations and translations

    std::vector<cv::Mat> rvecs, tvecs;

        // start calibration

        return

     calibrateCamera(objectPoints, // the 3D points

                            imagePoints,  // the image points

                                        imageSize,    // image size

                                        cameraMatrix, // output camera matrix

                                        distCoeffs,   // output distortion matrix

                                        rvecs, tvecs, // Rs, Ts 

                                        flag);        // set options

//                                      ,CV_CALIB_USE_INTRINSIC_GUESS);

}

// remove distortion in an image (after calibration)

cv::Mat CameraCalibrator::remap(const cv::Mat &image) {

        cv::Mat undistorted;

        if (mustInitUndistort) { // called once per calibration

                cv::initUndistortRectifyMap(

                        cameraMatrix,  // computed camera matrix

            distCoeffs,    // computed distortion matrix

            cv::Mat(),     // optional rectification (none) 

                        cv::Mat(),     // camera matrix to generate undistorted

                        cv::Size(640,480),

//            image.size(),  // size of undistorted

            CV_32FC1,      // type of output map

            map1, map2);   // the x and y mapping functions

                mustInitUndistort= false;

        }

        // Apply mapping functions

    cv::remap(image, undistorted, map1, map2,

                cv::INTER_LINEAR); // interpolation type

        return undistorted;

}

// Set the calibration options

// 8radialCoeffEnabled should be true if 8 radial coefficients are required (5 is default)

// tangentialParamEnabled should be true if tangeantial distortion is present

void CameraCalibrator::setCalibrationFlag(bool radial8CoeffEnabled, bool tangentialParamEnabled) {

    // Set the flag used in cv::calibrateCamera()

    flag = 0;

    if (!tangentialParamEnabled) flag += CV_CALIB_ZERO_TANGENT_DIST;

        if (radial8CoeffEnabled) flag += CV_CALIB_RATIONAL_MODEL;

}