/*------------------------------------------------------------------------------------------*\
   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 (unsigned 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() == (unsigned int) 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;
}