PCLVisualizer: save and restore camera information

Press ctrl + s to save camera parameters and ctrl + r to restore the
saved camera parameters.

If a camera file is specified with "-cam" option or pcd file(s) is(are)
available in the command line, the camera parameters will be written to
the corresponding file and can be restored later from that file.
In this case, PCLVisualizer will restore camera parameters automatically
from the corresponding file when the pragram restarts with the same
command line input.

visualization/include/pcl/visualization/interactor_style.h

@@ -90,6 +90,8 @@ namespace pcl
       * -        g, G   : display scale grid (on/off)
       * -        u, U   : display lookup table (on/off)
       * -  r, R [+ ALT] : reset camera [to viewpoint = {0, 0, 0} -> center_{x, y, z}]
+      * -  CTRL + s, S  : save camera parameters
+      * -  CTRL + r, R  : restore camera parameters
       * -  ALT + s, S   : turn stereo mode on/off
       * -  ALT + f, F   : switch between maximized window mode and original size
       * -        l, L           : list all available geometric and color handlers for the current actor map
@@ -115,7 +117,7 @@ namespace pcl
           max_win_height_ (), max_win_width_ (), grid_enabled_ (), grid_actor_ (), lut_enabled_ (),
           lut_actor_ (), snapshot_writer_ (), wif_ (), mouse_signal_ (), keyboard_signal_ (),
           point_picking_signal_ (), area_picking_signal_ (), stereo_anaglyph_mask_default_ (),
-          mouse_callback_ (), modifier_ ()
+          mouse_callback_ (), modifier_ (), camera_file_ (), camera_ (), camera_saved_ (), win_ ()
         {}
 
         /** \brief Empty destructor */
@@ -184,6 +186,56 @@ namespace pcl
         void
         saveScreenshot (const std::string &file);
 
+        /** \brief Save the camera parameters to disk, as a .cam file.
+          * \param[in] file the name of the .cam file
+          */
+        bool
+        saveCameraParameters (const std::string &file);
+
+        /** \brief Get camera parameters and save them to a \ref pcl::visualization::Camera.
+          * \param[out] camera the name of the \ref pcl::visualization::Camera
+          */
+        void
+        getCameraParameters (Camera &camera);
+
+        /** \brief Load camera parameters from a camera parameter file.
+          * \param[in] file the name of the camera parameter file
+          */
+        bool
+        loadCameraParameters (const std::string &file);
+
+        /** \brief Set the camera parameters via an intrinsics and and extrinsics matrix
+          * \note This assumes that the pixels are square and that the center of the image is at the center of the sensor.
+          * \param[in] intrinsics the intrinsics that will be used to compute the VTK camera parameters
+          * \param[in] extrinsics the extrinsics that will be used to compute the VTK camera parameters
+          * \param[in] viewport the viewport to modify camera of (0 modifies all cameras)
+          */
+        void
+        setCameraParameters (const Eigen::Matrix3f &intrinsics, const Eigen::Matrix4f &extrinsics, int viewport = 0); 
+
+        /** \brief Set the camera parameters by given a full camera data structure.
+          * \param[in] camera camera structure containing all the camera parameters.
+          * \param[in] viewport the viewport to modify camera of (0 modifies all cameras)
+          */
+        void
+        setCameraParameters (const Camera &camera, int viewport = 0);
+
+        /** \brief Set camera file for camera parameter saving/restoring.
+          * \param[in] file the name of the camera parameter file
+          */
+        void
+        setCameraFile (const std::string file)
+        {
+          camera_file_ = file;
+        }
+
+        /** \brief Get camera file for camera parameter saving/restoring. */
+        std::string
+        getCameraFile () const
+        {
+          return (camera_file_);
+        }
+
         /** \brief Change the default keyboard modified from ALT to a different special key.
           * Allowed values are:
           * - INTERACTOR_KB_MOD_ALT
@@ -284,6 +336,21 @@ namespace pcl
         void 
         zoomOut ();
 
+        /** \brief Get camera parameters from a string vector.
+          * \param[in] camera A string vector:
+          * Clipping Range, Focal Point, Position, ViewUp, Distance, Field of View Y, Window Size, Window Pos.
+          * Values in each string are seperated by a ','
+          */
+        bool
+        getCameraParameters (const std::vector<std::string> &camera);
+
+        /** \brief Set render window. */
+        void
+        setRenderWindow (const vtkSmartPointer<vtkRenderWindow> &win)
+        {
+          win_ = win;
+        }
+
         /** \brief True if we're using red-blue colors for anaglyphic stereo, false if magenta-green. */
         bool stereo_anaglyph_mask_default_;
 
@@ -293,7 +360,19 @@ namespace pcl
         /** \brief The keyboard modifier to use. Default: Alt. */
         InteractorKeyboardModifier modifier_;
 
+        /** \brief Camera file for camera parameter saving/restoring. */
+        std::string camera_file_;
+        /** \brief A \ref pcl::visualization::Camera for camera parameter saving/restoring. */
+        Camera camera_;
+        /** \brief A \ref pcl::visualization::Camera is saved or not. */
+        bool camera_saved_;
+        /** \brief The render window.
+          * Only used when interactor maybe not available
+          */
+        vtkSmartPointer<vtkRenderWindow> win_;
+
         friend class PointPickingCallback;
+        friend class PCLVisualizer;
     };
 
     /** \brief PCL histogram visualizer interactory style class.

visualization/include/pcl/visualization/pcl_visualizer.h

@@ -1595,7 +1595,15 @@ namespace pcl
         bool
         getCameraParameters (int argc, char **argv);
 
-        /** \brief Checks whether the camera parameters were manually loaded from file.*/
+        /** \brief Load camera parameters from a camera parameters file.
+          * \param[in] file the name of the camera parameters file
+          */
+        bool
+        loadCameraParameters (const std::string &file);
+
+        /** \brief Checks whether the camera parameters were manually loaded.
+          * \return True if valid "-cam" option is available in command line or a corresponding camera file is automatically loaded.
+          */
         bool
         cameraParamsSet () const;
 
@@ -1689,6 +1697,18 @@ namespace pcl
         void
         saveScreenshot (const std::string &file);
 
+        /** \brief Save the camera parameters to disk, as a .cam file.
+          * \param[in] file the name of the .cam file
+          */
+        void
+        saveCameraParameters (const std::string &file);
+
+        /** \brief Get camera parameters and save them to a pcl::visualization::Camera.
+          * \param[out] camera the name of the pcl::visualization::Camera
+          */
+        void
+        getCameraParameters (Camera &camera);
+
         /** \brief Return a pointer to the underlying VTK Render Window used. */
         vtkSmartPointer<vtkRenderWindow>
         getRenderWindow ()
@@ -2063,6 +2083,13 @@ namespace pcl
         int
         textureFromTexMaterial (const pcl::TexMaterial& tex_mat,
                                 vtkTexture* vtk_tex) const;
+
+        /** \brief Get camera file for camera parameter saving/restoring from command line.
+          * Camera filename is calculated using sha1 value of all pathes of input .pcd files
+          * \return empty string if failed.
+          */
+        std::string
+        getUniqueCameraFile (int argc, char **argv);
 
         //There's no reason these conversion functions shouldn't be public and static so others can use them.
       public: