CObservation3DRangeScan.h

Go to the documentation of this file.

/* +---------------------------------------------------------------------------+
   |          The Mobile Robot Programming Toolkit (MRPT) C++ library          |
   |                                                                           |
   |                       http://www.mrpt.org/                                |
   |                                                                           |
   |   Copyright (C) 2005-2011  University of Malaga                           |
   |                                                                           |
   |    This software was written by the Machine Perception and Intelligent    |
   |      Robotics Lab, University of Malaga (Spain).                          |
   |    Contact: Jose-Luis Blanco  <jlblanco@ctima.uma.es>                     |
   |                                                                           |
   |  This file is part of the MRPT project.                                   |
   |                                                                           |
   |     MRPT is free software: you can redistribute it and/or modify          |
   |     it under the terms of the GNU General Public License as published by  |
   |     the Free Software Foundation, either version 3 of the License, or     |
   |     (at your option) any later version.                                   |
   |                                                                           |
   |   MRPT is distributed in the hope that it will be useful,                 |
   |     but WITHOUT ANY WARRANTY; without even the implied warranty of        |
   |     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         |
   |     GNU General Public License for more details.                          |
   |                                                                           |
   |     You should have received a copy of the GNU General Public License     |
   |     along with MRPT.  If not, see <http://www.gnu.org/licenses/>.         |
   |                                                                           |
   +---------------------------------------------------------------------------+ */
#ifndef CObservation3DRangeScan_H
#define CObservation3DRangeScan_H

#include <mrpt/utils/CSerializable.h>
#include <mrpt/utils/CImage.h>
#include <mrpt/slam/CObservation.h>
#include <mrpt/poses/CPose3D.h>
#include <mrpt/poses/CPose2D.h>

#include <mrpt/math/CPolygon.h>


namespace mrpt
{
namespace slam
{

        DEFINE_SERIALIZABLE_PRE_CUSTOM_BASE_LINKAGE( CObservation3DRangeScan, CObservation,OBS_IMPEXP )

        /** Declares a class derived from "CObservation" that
         *      encapsules a 3D range scan measurement (e.g. from a time of flight range camera).
         *  This kind of observations can carry one or more of these data fields:
         *    - 3D point cloud (as float's).
         *    - 2D range image (as a matrix): Each entry in the matrix "rangeImage(ROW,COLUMN)" contains a distance or a depth (in meters), depending on \a range_is_depth.
         *    - 2D intensity (grayscale or RGB) image (as a mrpt::utils::CImage): For SwissRanger cameras, a logarithmic A-law compression is used to convert the original 16bit intensity to a more standard 8bit graylevel.
         *    - 2D confidence image (as a mrpt::utils::CImage): For each pixel, a 0x00 and a 0xFF mean the lowest and highest confidence levels, respectively.
         *
         *  The coordinates of the 3D point cloud are in meters with respect to the depth camera origin of coordinates
         *    (in SwissRanger, the front face of the camera: a small offset ~1cm in front of the physical focal point),
         *    with the +X axis pointing forward, +Y pointing left-hand and +Z pointing up.
         *  The field CObservation3DRangeScan::relativePoseIntensityWRTDepth describes the change of coordinates from
         *    the depth camera to the intensity (RGB or grayscale) camera. In a SwissRanger camera both cameras coincide,
         *    so this pose is just a rotation (0,0,0,-90deg,0,-90deg). But in
         *    Microsoft Kinect there is also an offset, as shown in this figure:
         *
         *  <div align=center>
         *   <img src="CObservation3DRangeScan_figRefSystem.png">
         *  </div>
         *
         *  In any case, check the field \a relativePoseIntensityWRTDepth, or the method \a doDepthAndIntensityCamerasCoincide()
         *    to determine if both frames of reference coincide, since even for Kinect cameras both can coincide if the images
         *    have been rectified.
         *
         *  The 2D images and matrices are stored as common images, with an up->down rows order and left->right, as usual.
         *   Optionally, the intensity and confidence channels can be set to delayed-load images for off-rawlog storage so it saves
         *   memory by having loaded in memory just the needed images. See the methods load() and unload().
         *  Due to the intensive storage requirements of this kind of observations, this observation is the only one in MRPT
         *   for which it's recommended to always call "load()" and "unload()" before and after using the observation, *ONLY* when
         *   the observation was read from a rawlog dataset, in order to make sure that all the externally stored data fields are
         *   loaded and ready in memory.
         *
         *  Classes that grab observations of this type are:
         *              - mrpt::hwdrivers::CSwissRanger3DCamera
         *              - mrpt::hwdrivers::CKinect
         *
         *  There are two sets of calibration parameters:
         *              - cameraParams: Projection parameters of the depth camera.
         *              - cameraParamsIntensity: Projection parameters of the intensity (gray-level or RGB) camera.
         *
         *  In some cameras, like SwissRanger, both are the same. Also, it is possible in Kinect to rectify the range images such both cameras
         *   seem to coincide and then both sets of camera parameters will be identical.
         *
         *  Range data can be interpreted in two different ways depending on the 3D camera (this field is already set to the
         *    correct setting when grabbing observations from an mrpt::hwdrivers sensor):
         *              - range_is_depth=true  -> Kinect-like ranges: entries of \a rangeImage are distances along the +X axis
         *              - range_is_depth=false -> Ranges in \a rangeImage are actual distances in 3D.
         *
         *  3D point clouds can be generated at any moment after grabbing with CObservation3DRangeScan::project3DPointsFromDepthImage()
         *
         *  \note Starting at serialization version 2 (MRPT 0.9.1+), the confidence channel is stored as an image instead of a matrix to optimize memory and disk space.
         *  \note Starting at serialization version 3 (MRPT 0.9.1+), the 3D point cloud and the rangeImage can both be stored externally to save rawlog space.
         *  \note Starting at serialization version 5 (MRPT 0.9.5+), the new field \a range_is_depth.
         *
         * \sa mrpt::hwdrivers::CSwissRanger3DCamera, mrpt::hwdrivers::CKinect, CObservation
         * \ingroup mrpt_obs_grp
         */
        class OBS_IMPEXP CObservation3DRangeScan : public CObservation
        {
                // This must be added to any CSerializable derived class:
                DEFINE_SERIALIZABLE( CObservation3DRangeScan )

        protected:
                bool                    m_points3D_external_stored; //!< If set to true, m_points3D_external_file is valid.
                std::string             m_points3D_external_file;   //!< 3D points are in CImage::IMAGES_PATH_BASE+<this_file_name>

                bool                    m_rangeImage_external_stored; //!< If set to true, m_rangeImage_external_file is valid.
                std::string             m_rangeImage_external_file;   //!< rangeImage is in CImage::IMAGES_PATH_BASE+<this_file_name>

        public:
                CObservation3DRangeScan( );                             //!< Default constructor
                virtual ~CObservation3DRangeScan( );    //!< Destructor

                /** @name Delayed-load manual control methods.
                    @{ */
                /** Makes sure all images and other fields which may be externally stored are loaded in memory.
                  *  Note that for all CImages, calling load() is not required since the images will be automatically loaded upon first access, so load() shouldn't be needed to be called in normal cases by the user.
                  *  If all the data were alredy loaded or this object has no externally stored data fields, calling this method has no effects.
                  * \sa unload
                  */
                virtual void load() const;
                /** Unload all images, for the case they being delayed-load images stored in external files (othewise, has no effect).
                  * \sa load
                  */
                virtual void unload();
                /** @} */

                /** Compute the 3D points coordinates from the depth image (\a rangeImage) and the depth camera camera parameters (\a cameraParams).
                  *  There exist two set of formulas for projecting the i'th point, depending on the value of "range_is_depth".
                  *   In all formulas below, "rangeImage" is the matrix of ranges and the pixel coordinates are (r,c).
                  *
                  *  1) [range_is_depth=true] With "range equals depth" or "Kinect-like depth mode": the range values
                  *      are in fact distances along the "+X" axis, not real 3D ranges (this is the way Kinect reports ranges):
                  *
                  * \code
                  *   x(i) = rangeImage(r,c)
                  *   y(i) = (r_cx - c) * x(i) / r_fx
                  *   z(i) = (r_cy - r) * x(i) / r_fy
                  * \endcode
                  *
                  *
                  *  2) [range_is_depth=false] With "normal ranges": range means distance in 3D. This must be set when
                  *      processing data from the SwissRange 3D camera, among others.
                  *
                  * \code
                  *   Ky = (r_cx - c)/r_fx
                  *   Kz = (r_cy - r)/r_fy
                  *
                  *   x(i) = rangeImage(r,c) / sqrt( 1 + Ky^2 + Kz^2 )
                  *   y(i) = Ky * x(i)
                  *   z(i) = Kz * x(i)
                  * \endcode
                  *
                  * \param[in] PROJ3D_USE_LUT (Only when range_is_depth=true) Whether to use a Look-up-table (LUT) to speed up the conversion. It's thread safe in all situations <b>except</b> when you call this method from different threads <b>and</b> with different camera parameter matrices. In all other cases, it's a good idea to left it enabled.
                  *
                  * \note In MRPT < 0.9.5, this method always assumes that ranges were in Kinect-like format.
                  */
                void project3DPointsFromDepthImage(const bool PROJ3D_USE_LUT=true);

                bool hasPoints3D;                                                               //!< true means the field points3D contains valid data.
                std::vector<float> points3D_x;   //!< If hasPoints3D=true, the X coordinates of the 3D point cloud detected by the camera. \sa resizePoints3DVectors
                std::vector<float> points3D_y;   //!< If hasPoints3D=true, the Y coordinates of the 3D point cloud detected by the camera. \sa resizePoints3DVectors
                std::vector<float> points3D_z;   //!< If hasPoints3D=true, the Z coordinates of the 3D point cloud detected by the camera. \sa resizePoints3DVectors

                /** Use this method instead of resizing all three \a points3D_x, \a points3D_y & \a points3D_z to allow the usage of the internal memory pool. */
                void resizePoints3DVectors(const size_t nPoints);

                // 3D points external storage functions ---------
                inline bool points3D_isExternallyStored() const { return m_points3D_external_stored; }
                inline std::string points3D_getExternalStorageFile() const { return m_points3D_external_file; }
                void points3D_getExternalStorageFileAbsolutePath(std::string &out_path) const;
                inline std::string points3D_getExternalStorageFileAbsolutePath() const {
                                std::string tmp;
                                points3D_getExternalStorageFileAbsolutePath(tmp);
                                return tmp;
                }
                void points3D_convertToExternalStorage( const std::string &fileName, const std::string &use_this_base_dir ); //!< Users won't normally want to call this, it's only used from internal MRPT programs.
                // ---------

                bool hasRangeImage;                             //!< true means the field rangeImage contains valid data
                mrpt::math::CMatrix rangeImage;         //!< If hasRangeImage=true, a matrix of floats with the range data as captured by the camera (in meters) \sa range_is_depth
                bool range_is_depth;                            //!< true: Kinect-like ranges: entries of \a rangeImage are distances along the +X axis; false: Ranges in \a rangeImage are actual distances in 3D.

                void rangeImage_setSize(const int HEIGHT, const int WIDTH); //!< Similar to calling "rangeImage.setSize(H,W)" but this method provides memory pooling to speed-up the memory allocation.

                // Range Matrix external storage functions ---------
                inline bool rangeImage_isExternallyStored() const { return m_rangeImage_external_stored; }
                inline std::string rangeImage_getExternalStorageFile() const { return m_rangeImage_external_file; }
                void rangeImage_getExternalStorageFileAbsolutePath(std::string &out_path) const;
                inline std::string rangeImage_getExternalStorageFileAbsolutePath() const {
                                std::string tmp;
                                rangeImage_getExternalStorageFileAbsolutePath(tmp);
                                return tmp;
                }
                void rangeImage_convertToExternalStorage( const std::string &fileName, const std::string &use_this_base_dir ); //!< Users won't normally want to call this, it's only used from internal MRPT programs.
                /** Forces marking this observation as non-externally stored - it doesn't anything else apart from reseting the corresponding flag (Users won't normally want to call this, it's only used from internal MRPT programs) */
                void rangeImage_forceResetExternalStorage() { m_rangeImage_external_stored=false; }
                // ---------

                bool hasIntensityImage;                         //!< true means the field intensityImage contains valid data
                mrpt::utils::CImage intensityImage;     //!< If hasIntensityImage=true, a color or gray-level intensity image of the same size than "rangeImage"

                bool hasConfidenceImage;                        //!< true means the field confidenceImage contains valid data
                mrpt::utils::CImage confidenceImage;  //!< If hasConfidenceImage=true, an image with the "confidence" value [range 0-255] as estimated by the capture drivers.

                mrpt::utils::TCamera    cameraParams;   //!< Projection parameters of the depth camera.
                mrpt::utils::TCamera    cameraParamsIntensity;  //!< Projection parameters of the intensity (graylevel or RGB) camera.

                /** Relative pose of the intensity camera wrt the depth camera (which is the coordinates origin for this observation).
                  *  In a SwissRanger camera, this will be (0,0,0,-90deg,0,-90deg) since both cameras coincide.
                  *  In a Kinect, this will include a small lateral displacement and a rotation, according to the drawing on the top of this page.
                  *  \sa doDepthAndIntensityCamerasCoincide
                  */
                mrpt::poses::CPose3D    relativePoseIntensityWRTDepth;

                /** Return true if \a relativePoseIntensityWRTDepth equals the pure rotation (0,0,0,-90deg,0,-90deg) (with a small comparison epsilon)
                  * \sa relativePoseIntensityWRTDepth
                  */
                bool doDepthAndIntensityCamerasCoincide() const;


                float   maxRange;       //!< The maximum range allowed by the device, in meters (e.g. 8.0m, 5.0m,...)
                CPose3D sensorPose;     //!< The 6D pose of the sensor on the robot.
                float   stdError;       //!< The "sigma" error of the device in meters, used while inserting the scan in an occupancy grid.


                /** A general method to retrieve the sensor pose on the robot.
                  *  Note that most sensors will return a full (6D) CPose3D, but see the derived classes for more details or special cases.
                  * \sa setSensorPose
                  */
                void getSensorPose( CPose3D &out_sensorPose ) const { out_sensorPose = sensorPose; }

                /** A general method to change the sensor pose on the robot.
                  *  Note that most sensors will use the full (6D) CPose3D, but see the derived classes for more details or special cases.
                  * \sa getSensorPose
                  */
                void setSensorPose( const CPose3D &newSensorPose ) { sensorPose = newSensorPose; }

                void swap(CObservation3DRangeScan &o);  //!< Very efficient method to swap the contents of two observations.

                void getZoneAsObs( CObservation3DRangeScan &obs, const unsigned int &r1, const unsigned int &r2, const unsigned int &c1, const unsigned int &c2 );

                /** A Levenberg-Marquart-based optimizer to recover the calibration parameters of a 3D camera given a range (depth) image and the corresponding 3D point cloud.
                  * \param camera_offset The offset (in meters) in the +X direction of the point cloud. It's 1cm for SwissRanger SR4000.
                  * \return The final average reprojection error per pixel (typ <0.05 px)
                  */
                static double recoverCameraCalibrationParameters(
                        const CObservation3DRangeScan   &in_obs,
                        mrpt::utils::TCamera                    &out_camParams,
                        const double camera_offset = 0.01 );


        }; // End of class def.


        } // End of namespace

        namespace utils
        {
                using namespace ::mrpt::slam;
                // Specialization must occur in the same namespace
                MRPT_DECLARE_TTYPENAME_PTR(CObservation3DRangeScan)
        }

} // End of namespace

#endif