class mrpt::hwdrivers::CCameraSensor

Overview

The central class for camera grabbers in MRPT, implementing the “generic sensor” interface.

This class provides the user with a uniform interface to a variety of other classes which manage only one specific camera “driver” (opencv, ffmpeg, PGR FlyCapture,…)

Following the “generic sensor” interface, all the parameters must be passed int the form of a configuration file, which may be also formed on the fly (without being a real config file) as in this example:

CCameraSensor myCam;
const string str =
   "[CONFIG]\n"
   "grabber_type=opencv\n";

CConfigFileMemory cfg(str);
myCam.loadConfig(cfg,"CONFIG");
myCam.initialize();
CObservation::Ptr obs = myCam.getNextFrame();

Images can be retrieved through the normal “doProcess()” interface, or the specific method “getNextFrame()”.

Some notes:

• “grabber_type” determines the class to use internally for image capturing (see below).

• For the meaning of cv_camera_type and other parameters, refer to mrpt::hwdrivers::CImageGrabber_OpenCV

• For the parameters of dc1394 parameters, refer to generic IEEE1394 documentation, and to mrpt::hwdrivers::TCaptureOptions_dc1394.

• If the high number of existing parameters annoy you, try the function prepareVideoSourceFromUserSelection(), which displays a GUI dialog to the user so he/she can choose the desired camera & its parameters.

Images can be saved in the “external storage” mode. Detached threads are created for this task. See setPathForExternalImages() and setExternalImageFormat(). These methods are called automatically from the app rawlog-grabber.

These is the list of all accepted parameters:

 PARAMETERS IN THE ".INI"-LIKE CONFIGURATION STRINGS:
-------------------------------------------------------
  [supplied_section_name]
   # Select one of the grabber implementations -----------------------
   grabber_type       = opencv | dc1394 | bumblebee_dc1394 | ffmpeg | rawlog
| swissranger | svs | kinect | flycap | flycap_stereo | image_dir | myntd

   #  Options for any grabber_type ------------------------------------
   preview_decimation = 0     // N<=0 (or not present): No preview; N>0,
display 1 out of N captured frames.
   preview_reduction  = 0     // 0 or 1 (or not present): The preview shows
the actual image. For 2,3,..., reduces the size of the image by that factor,
only for the preview window.
   capture_grayscale  = 0     // 1:capture in grayscale, whenever the driver
allows it. Default=0
   #  For externaly stored images, the format of image files (default=jpg)
   #external_images_format  = jpg

   #  For externaly stored images: whether to spawn independent threads to
save the image files.
   #external_images_own_thread  = 1   // 0 or 1

   # If external_images_own_thread=1, this changes the number of threads to
launch
   #  to save image files. The default is determined from
mrpt::system::getNumberOfProcessors()
   #  and should be OK unless you want to save processor time for other
things.
   #external_images_own_thread_count = 2    // >=1

   # (Only when external_images_format=jpg): Optional parameter to set the
JPEG compression quality:
   #external_images_jpeg_quality = 95    // [1-100]. Default: 95

   # Pose of the sensor on the robot:
   pose_x=0     ; (meters)
   pose_y=0
   pose_z=0
   pose_yaw=0   ; (Angles in degrees)
   pose_pitch=0
   pose_roll=0

   # Options for grabber_type= opencv  ------------------------------------
   cv_camera_index  = 0       // [opencv] Number of camera to open
   cv_camera_type   = CAMERA_CV_AUTODETECT
   cv_frame_width   = 640     // [opencv] Capture width (not present or set
to 0 for default)
   cv_frame_height  = 480     // [opencv] Capture height (not present or set
to 0 for default)
   cv_fps           = 15      // [opencv] IEEE1394 cams only: Capture FPS
(not present or 0 for default)
   cv_gain          = 0       // [opencv] Camera gain, if available (nor
present or set to 0 for default).

   # Options for grabber_type= dc1394 -------------------------------------
   dc1394_camera_guid   = 0 | 0x11223344    // 0 (or not present): the first
camera; A hexadecimal number: The GUID of the camera to open
   dc1394_camera_unit   = 0                 // 0 (or not present): the first
camera; 0,1,2,...: The unit number (within the given GUID) of the camera to
open (Stereo cameras: 0 or 1)
   dc1394_frame_width   = 640
   dc1394_frame_height  = 480
   dc1394_framerate     = 15                    // eg: 7.5, 15, 30, 60,
etc... For possibilities see mrpt::hwdrivers::TCaptureOptions_dc1394
   dc1394_mode7         = -1                    // -1: Ignore, i>=0, set to
MODE7_i
   dc1394_color_coding  = COLOR_CODING_YUV422   // For possibilities see
mrpt::hwdrivers::TCaptureOptions_dc1394
   # Options for setting feature values: dc1394_<feature> = <n>
   # with <feature> = brightness | exposure | sharpness | white_balance |
gamma | shutter | gain
   #      <n> a value, or -1 (or not present) for not to change this feature
value in the camera, possible values are shown in execution
   dc1394_shutter       = -1
   # Options for setting feature modes: dc1394_<feature>_mode = <n>
   # with <feature> = brightness | exposure | sharpness | white_balance |
gamma | shutter | gain
   #      <n> = -1 (or not present) [not to change] | 0 [manual] | 1 [auto]
| 2 [one_push_auto]
   dc1394_shutter_mode  = -1
   # Options for setting trigger options:
   dc1394_trigger_power = -1    // -1 (or not present) for not to change
| 0 [OFF] | 1 [ON]
   dc1394_trigger_mode  = -1    // -1 (or not present) for not to change |
0..7 corresponding to possible modes 0,1,2,3,4,5,14,15
   dc1394_trigger_source= -1    // -1 (or not present) for not to change |
0..4 corresponding to possible sources 0,1,2,3,SOFTWARE
   dc1394_trigger_polarity = -1 // -1 (or not present) for not to change | 0
[ACTIVE_LOW] | 1 [ACTIVE_HIGH]
   dc1394_ring_buffer_size = 15  // Length of frames ring buffer (internal
to libdc1394)

   # Options for grabber_type= bumblebee_dc1394
----------------------------------
   bumblebee_dc1394_camera_guid   = 0 | 0x11223344  // 0 (or not present):
the first camera; A hexadecimal number: The GUID of the camera to open
   bumblebee_dc1394_camera_unit   = 0               // 0 (or not present):
the first camera; 0,1,2,...: The unit number (within the given GUID) of the
camera to open (Stereo cameras: 0 or 1)
   bumblebee_dc1394_framerate     = 15              // eg: 7.5, 15, 30,
60, etc... For possibilities see mrpt::hwdrivers::TCaptureOptions_dc1394

   # Options for grabber_type= ffmpeg -------------------------------------
   ffmpeg_url             = rtsp://127.0.0.1      // [ffmpeg] The video file
or IP camera to open

   # Options for grabber_type= rawlog -------------------------------------
   rawlog_file            = mylog.rawlog          // [rawlog] This can be
used to simulate the capture of images already grabbed in the past in the
form of a MRPT rawlog.
   rawlog_camera_sensor_label  = CAMERA1          // [rawlog] If this field
is not present, all images found in the rawlog will be retrieved. Otherwise,
only those observations with a matching sensor label.

   # Options for grabber_type= svs -------------------------------------
   svs_camera_index = 0
   svs_frame_width = 800
   svs_frame_height = 600
   svs_framerate = 25.0
   svs_NDisp = ...
   svs_Corrsize = ...
   svs_LR = ...
   svs_Thresh = ...
   svs_Unique = ...
   svs_Horopter = ...
   svs_SpeckleSize = ...
   svs_procesOnChip = false
   svs_calDisparity = true

   # Options for grabber_type= swissranger
-------------------------------------
   sr_use_usb         = true            // True: use USB, false: use
ethernet
   sr_IP              = 192.168.2.14    // If sr_use_usb=false, the camera
IP
   sr_grab_grayscale  = true            // whether to save the intensity
channel
   sr_grab_3d         = true            // whether to save the 3D points
   sr_grab_range      = true            // whether to save the range image
   sr_grab_confidence = true            // whether to save the confidence
image

   # Options for grabber_type= XBox kinect
-------------------------------------
   kinect_grab_intensity  = true            // whether to save the intensity
(RGB) channel
   kinect_grab_3d         = true            // whether to save the 3D points
   kinect_grab_range      = true            // whether to save the depth
image
   #kinect_video_rgb       = true            // Optional. If set to "false",
the IR intensity channel will be grabbed instead of the color RGB channel.

   # Options for grabber_type= flycap (Point Grey Research's FlyCapture 2
for Monocular and Stereo cameras, e.g. Bumblebee2) --------
   flycap_camera_index           = 0
   #... (all the parameters enumerated in
mrpt::hwdrivers::TCaptureOptions_FlyCapture2 with the prefix "flycap_")

   # Options for grabber_type= flycap_stereo (Point Grey Research's
FlyCapture 2, two cameras setup as a stereo pair) ------
   # fcs_start_synch_capture   = false  // *Important*: Only set to true if
using Firewire cameras: the "startSyncCapture()" command is unsupported in
USB3 and GigaE cameras.

   fcs_LEFT_camera_index           = 0
   #... (all the parameters enumerated in
mrpt::hwdrivers::TCaptureOptions_FlyCapture2 with the prefix "fcs_LEFT_")
   fcs_RIGHT_camera_index          = 0
   #... (all the parameters enumerated in
mrpt::hwdrivers::TCaptureOptions_FlyCapture2 with the prefix "fcs_RIGHT_")

   # Options for grabber_type= image_dir
   image_dir_url                    =               // [string] URL of the
directory
   left_filename_format             = imL_%05d.jpg  // [string] Format
including prefix, number of trailing zeros, digits and image format
(extension)
   right_filename_format            = imR_%05d.jpg  // [string] Format
including prefix, number of trailing zeros, digits and image format
(extension). Leave blank if only images from one camera will be used.
   start_index                      = 0             // [int]
Starting index for images
   end_index                        = 100           // [int]    End index
for the images

   # Options for grabber_type= myntd  ------------------------------------
   myntd_xxx  =

The execution rate, in rawlog-grabber or the user code calling doProcess(), should be greater than the required capture FPS.

In Linux you may need to execute “chmod 666 /dev/video1394/ * ” and “chmod 666 /dev/raw1394” for allowing any user R/W access to firewire cameras.

[New in MRPT 1.4.0] The bumblebee driver has been deleted, use the flycap driver in stereo mode.

See also:

mrpt::hwdrivers::CImageGrabber_OpenCV, mrpt::hwdrivers::CImageGrabber_dc1394, CGenericSensor, prepareVideoSourceFromUserSelection()

#include <mrpt/hwdrivers/CCameraSensor.h>

class CCameraSensor:
    public mrpt::system::COutputLogger,
    public mrpt::hwdrivers::CGenericSensor
{
public:
    // typedefs

    typedef std::shared_ptr<CCameraSensor> Ptr;
    typedef std::function<void(const mrpt::obs::CObservation::Ptr&obs, void*user_ptr)> TPreSaveUserHook;

    // construction

    CCameraSensor();

    // methods

    virtual void doProcess();
    mrpt::obs::CObservation::Ptr getNextFrame();
    void getNextFrame(std::vector<mrpt::serialization::CSerializable::Ptr>& out_obs);
    virtual void initialize();
    void close();
    void setSoftwareTriggerLevel(bool level);
    void setPathForExternalImages(const std::string& directory);
    void enableLaunchOwnThreadForSavingImages(bool enable = true);
    void addPreSaveHook(TPreSaveUserHook user_function, void* user_ptr);
};

Inherited Members

public:
    // structs

    struct TMsg;

    // methods

    CGenericSensor& operator = (const CGenericSensor&);
    virtual void doProcess() = 0;

Typedefs

typedef std::function<void(const mrpt::obs::CObservation::Ptr&obs, void*user_ptr)> TPreSaveUserHook

Functor type.

Construction

CCameraSensor()

Constructor.

The camera is not open until “initialize” is called.

Methods

virtual void doProcess()

This method will be invoked at a minimum rate of “process_rate” (Hz)

Parameters:

This	method must throw an exception with a descriptive message if some critical error is found.

mrpt::obs::CObservation::Ptr getNextFrame()

Retrieves the next frame from the video source, raising an exception on any error.

Note: The returned observations can be of one of these classes (you can use IS_CLASS(obs,CObservationXXX) to determine it):

• mrpt::obs::CObservationImage (For normal cameras or video sources)

• mrpt::obs::CObservationStereoImages (For stereo cameras)

• mrpt::obs::CObservation3DRangeScan (For 3D cameras)

virtual void initialize()

Tries to open the camera, after setting all the parameters with a call to loadConfig.

Parameters:

This	method must throw an exception with a descriptive message if some critical error is found.

void close()

Close the camera (if open).

This method is called automatically on destruction.

void setSoftwareTriggerLevel(bool level)

Set Software trigger level value (ON or OFF) for cameras with this function available.

void setPathForExternalImages(const std::string& directory)

Set the path where to save off-rawlog image files (this class DOES take into account this path).

An empty string (the default value at construction) means to save images embedded in the rawlog, instead of on separate files.

Parameters:

std::exception

If the directory doesn’t exists and cannot be created.

void enableLaunchOwnThreadForSavingImages(bool enable = true)

This must be called before initialize()

void addPreSaveHook(TPreSaveUserHook user_function, void* user_ptr)

Provides a “hook” for user-code to be run BEFORE an image is going to be saved to disk if external storage is enabled (e.g.

to rectify images, preprocess them, etc.) Notice that this code may be called from detached threads, so it must be thread safe. If used, call this before initialize()