chessboard_camera_calib.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2019, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

#pragma once

#include <mrpt/img/CImage.h>
#include <mrpt/math/CMatrixFixed.h>
#include <mrpt/poses/CPose3D.h>
#include <mrpt/vision/types.h>

namespace mrpt::vision
{
/** \addtogroup chessboard_calib Chessboard calibration
 *  \ingroup mrpt_vision_grp
 *  @{  */

/** Data associated to each image in the calibration process
 * mrpt::vision::checkerBoardCameraCalibration (All the information can be left
 * empty and will be filled up in the calibration method).
 */
struct TImageCalibData
{
    /** This image will be automatically loaded from the file name passed to
     * checkerBoardCameraCalibration */
    mrpt::img::CImage img_original;
    /** At output, this will contain the detected checkerboard overprinted to
     * the image. */
    mrpt::img::CImage img_checkboard;
    /** At output, this will be the rectified image */
    mrpt::img::CImage img_rectified;
    /** At output, the detected corners (x,y) in pixel units. */
    std::vector<mrpt::img::TPixelCoordf> detected_corners;
    /** At output, the reconstructed pose of the camera. */
    mrpt::poses::CPose3D reconstructed_camera_pose;
    /** At output, only will have an empty vector if the checkerboard was not
     * found in this image, or the predicted (reprojected) corners, which were
     * used to estimate the average square error. */
    std::vector<mrpt::img::TPixelCoordf> projectedPoints_distorted;
    /** At output, like projectedPoints_distorted but for the undistorted image.
     */
    std::vector<mrpt::img::TPixelCoordf> projectedPoints_undistorted;

    /** Empty all the data */
    void clear() { *this = TImageCalibData(); }
};

/**  A list of images, used in checkerBoardCameraCalibration
 * \sa checkerBoardCameraCalibration
 */
using TCalibrationImageList = std::map<std::string, TImageCalibData>;

/** Performs a camera calibration (computation of projection and distortion
 * parameters) from a sequence of captured images of a checkerboard.
 * \param input_images [IN/OUT] At input, this list must have one entry for
 * each image to process. At output the original, detected checkboard and
 * rectified images can be found here. See TImageCalibData.
 * \param check_size_x [IN] The number of squares in the checkerboard in the X
 * direction.
 * \param check_size_y [IN] The number of squares in the checkerboard in the Y
 * direction.
 * \param check_squares_length_X_meters [IN] The size of each square in the
 * checkerboard, in meters, in the X axis.
 * \param check_squares_length_Y_meters [IN] This will typically be equal to
 * check_squares_length_X_meters.
 * \param intrinsicParams [OUT] The 3x3 intrinsic parameters matrix. See
 * https://www.mrpt.org/Camera_Parameters
 * \param distortionParams [OUT] The 1x4 vector of distortion parameters: k1 k2
 * p1 p2. See https://www.mrpt.org/Camera_Parameters
 * \param normalize_image [IN] Select OpenCV flag
 * \param out_MSE  [OUT] If set to !=nullptr, the mean square error of the
 * reprojection will be stored here (in pixel units).
 * \param skipDrawDetectedImgs [IN] Whether to skip the generation of the
 * undistorted and detected images in each TImageCalibData
 * \param useScaramuzzaAlternativeDetector [IN] Whether to use an alternative
 * detector. See CImage::findChessboardCorners for more deatails and references.
 * \sa The <a href="http://www.mrpt.org/Application:camera-calib-gui"
 * >camera-calib-gui application</a> is a user-friendly GUI to this class.
 * \return false on any error (more info will be dumped to cout), or true on
 * success.
 * \sa CImage::findChessboardCorners, checkerBoardStereoCalibration
 */
bool checkerBoardCameraCalibration(
    TCalibrationImageList& images, unsigned int check_size_x,
    unsigned int check_size_y, double check_squares_length_X_meters,
    double check_squares_length_Y_meters, mrpt::img::TCamera& out_camera_params,
    bool normalize_image = true, double* out_MSE = nullptr,
    bool skipDrawDetectedImgs = false,
    bool useScaramuzzaAlternativeDetector = false);

/** \overload with matrix of intrinsic params instead of mrpt::img::TCamera
 */
bool checkerBoardCameraCalibration(
    TCalibrationImageList& images, unsigned int check_size_x,
    unsigned int check_size_y, double check_squares_length_X_meters,
    double check_squares_length_Y_meters,
    mrpt::math::CMatrixDouble33& intrinsicParams,
    std::vector<double>& distortionParams, bool normalize_image = true,
    double* out_MSE = nullptr, bool skipDrawDetectedImgs = false,
    bool useScaramuzzaAlternativeDetector = false);

/** @}  */  // end of grouping
}  // namespace mrpt::vision