mirror of
https://github.com/opencv/opencv.git
synced 2024-12-27 03:14:05 +08:00
134 lines
6.4 KiB
ReStructuredText
134 lines
6.4 KiB
ReStructuredText
*******
|
||
HighGUI
|
||
*******
|
||
|
||
.. highlight:: cpp
|
||
|
||
Using Kinect and other OpenNI compatible depth sensors
|
||
======================================================
|
||
|
||
Depth sensors compatible with OpenNI (Kinect, XtionPRO, ...) are supported through ``VideoCapture`` class. Depth map, RGB image and some other formats of output can be retrieved by using familiar interface of ``VideoCapture``.
|
||
|
||
In order to use depth sensor with OpenCV you should do the following preliminary steps:
|
||
|
||
#.
|
||
Install OpenNI library (from here http://www.openni.org/downloadfiles) and PrimeSensor Module for OpenNI (from here https://github.com/avin2/SensorKinect). The installation should be done to default folders listed in the instructions of these products, e.g.:
|
||
|
||
.. code-block:: text
|
||
|
||
OpenNI:
|
||
Linux & MacOSX:
|
||
Libs into: /usr/lib
|
||
Includes into: /usr/include/ni
|
||
Windows:
|
||
Libs into: c:/Program Files/OpenNI/Lib
|
||
Includes into: c:/Program Files/OpenNI/Include
|
||
PrimeSensor Module:
|
||
Linux & MacOSX:
|
||
Bins into: /usr/bin
|
||
Windows:
|
||
Bins into: c:/Program Files/Prime Sense/Sensor/Bin
|
||
|
||
If one or both products were installed to the other folders, the user should change corresponding CMake variables ``OPENNI_LIB_DIR``, ``OPENNI_INCLUDE_DIR`` or/and ``OPENNI_PRIME_SENSOR_MODULE_BIN_DIR``.
|
||
|
||
#.
|
||
Configure OpenCV with OpenNI support by setting ``WITH_OPENNI`` flag in CMake. If OpenNI is found in install folders OpenCV will be built with OpenNI library (see a status ``OpenNI`` in CMake log) whereas PrimeSensor Modules can not be found (see a status ``OpenNI PrimeSensor Modules`` in CMake log). Without PrimeSensor module OpenCV will be successfully compiled with OpenNI library, but ``VideoCapture`` object will not grab data from Kinect sensor.
|
||
|
||
#.
|
||
Build OpenCV.
|
||
|
||
VideoCapture can retrieve the following data:
|
||
|
||
#.
|
||
data given from depth generator:
|
||
* ``CAP_OPENNI_DEPTH_MAP`` - depth values in mm (CV_16UC1)
|
||
* ``CAP_OPENNI_POINT_CLOUD_MAP`` - XYZ in meters (CV_32FC3)
|
||
* ``CAP_OPENNI_DISPARITY_MAP`` - disparity in pixels (CV_8UC1)
|
||
* ``CAP_OPENNI_DISPARITY_MAP_32F`` - disparity in pixels (CV_32FC1)
|
||
* ``CAP_OPENNI_VALID_DEPTH_MASK`` - mask of valid pixels (not ocluded, not shaded etc.) (CV_8UC1)
|
||
#.
|
||
data given from RGB image generator:
|
||
* ``CAP_OPENNI_BGR_IMAGE`` - color image (CV_8UC3)
|
||
* ``CAP_OPENNI_GRAY_IMAGE`` - gray image (CV_8UC1)
|
||
|
||
In order to get depth map from depth sensor use ``VideoCapture::operator >>``, e. g. ::
|
||
|
||
VideoCapture capture( CAP_OPENNI );
|
||
for(;;)
|
||
{
|
||
Mat depthMap;
|
||
capture >> depthMap;
|
||
|
||
if( waitKey( 30 ) >= 0 )
|
||
break;
|
||
}
|
||
|
||
For getting several data maps use ``VideoCapture::grab`` and ``VideoCapture::retrieve``, e.g. ::
|
||
|
||
VideoCapture capture(0); // or CAP_OPENNI
|
||
for(;;)
|
||
{
|
||
Mat depthMap;
|
||
Mat bgrImage;
|
||
|
||
capture.grab();
|
||
|
||
capture.retrieve( depthMap, CAP_OPENNI_DEPTH_MAP );
|
||
capture.retrieve( bgrImage, CAP_OPENNI_BGR_IMAGE );
|
||
|
||
if( waitKey( 30 ) >= 0 )
|
||
break;
|
||
}
|
||
|
||
For setting and getting some property of sensor` data generators use ``VideoCapture::set`` and ``VideoCapture::get`` methods respectively, e.g. ::
|
||
|
||
VideoCapture capture( CAP_OPENNI );
|
||
capture.set( CAP_OPENNI_IMAGE_GENERATOR_OUTPUT_MODE, CAP_OPENNI_VGA_30HZ );
|
||
cout << "FPS " << capture.get( CAP_OPENNI_IMAGE_GENERATOR+CAP_PROP_FPS ) << endl;
|
||
|
||
Since two types of sensor's data generators are supported (image generator and depth generator), there are two flags that should be used to set/get property of the needed generator:
|
||
|
||
* CAP_OPENNI_IMAGE_GENERATOR -- A flag for access to the image generator properties.
|
||
|
||
* CAP_OPENNI_DEPTH_GENERATOR -- A flag for access to the depth generator properties. This flag value is assumed by default if neither of the two possible values of the property is not set.
|
||
|
||
Some depth sensors (for example XtionPRO) do not have image generator. In order to check it you can get ``CAP_OPENNI_IMAGE_GENERATOR_PRESENT`` property.
|
||
::
|
||
|
||
bool isImageGeneratorPresent = capture.get( CAP_PROP_OPENNI_IMAGE_GENERATOR_PRESENT ) != 0; // or == 1
|
||
|
||
|
||
Flags specifing the needed generator type must be used in combination with particular generator property. The following properties of cameras available through OpenNI interfaces are supported:
|
||
|
||
*
|
||
For image generator:
|
||
|
||
- ``CAP_PROP_OPENNI_OUTPUT_MODE`` -- Three output modes are supported: ``CAP_OPENNI_VGA_30HZ`` used by default (image generator returns images in VGA resolution with 30 FPS), ``CAP_OPENNI_SXGA_15HZ`` (image generator returns images in SXGA resolution with 15 FPS) and ``CAP_OPENNI_SXGA_30HZ`` (image generator returns images in SXGA resolution with 30 FPS, the mode is supported by XtionPRO Live); depth generator's maps are always in VGA resolution.
|
||
|
||
|
||
*
|
||
For depth generator:
|
||
|
||
- ``CAP_PROP_OPENNI_REGISTRATION`` -- Flag that registers the remapping depth map to image map by changing depth generator's view point (if the flag is ``"on"``) or sets this view point to its normal one (if the flag is ``"off"``). The registration process’s resulting images are pixel-aligned,which means that every pixel in the image is aligned to a pixel in the depth image.
|
||
|
||
Next properties are available for getting only:
|
||
|
||
- ``CAP_PROP_OPENNI_FRAME_MAX_DEPTH`` -- A maximum supported depth of Kinect in mm.
|
||
- ``CAP_PROP_OPENNI_BASELINE`` -- Baseline value in mm.
|
||
- ``CAP_PROP_OPENNI_FOCAL_LENGTH`` -- A focal length in pixels.
|
||
- ``CAP_PROP_FRAME_WIDTH`` -- Frame width in pixels.
|
||
- ``CAP_PROP_FRAME_HEIGHT`` -- Frame height in pixels.
|
||
- ``CAP_PROP_FPS`` -- Frame rate in FPS.
|
||
|
||
*
|
||
Some typical flags combinations "generator type + property" are defined as single flags:
|
||
|
||
- ``CAP_OPENNI_IMAGE_GENERATOR_OUTPUT_MODE = CAP_OPENNI_IMAGE_GENERATOR + CAP_PROP_OPENNI_OUTPUT_MODE``
|
||
- ``CAP_OPENNI_DEPTH_GENERATOR_BASELINE = CAP_OPENNI_DEPTH_GENERATOR + CAP_PROP_OPENNI_BASELINE``
|
||
- ``CAP_OPENNI_DEPTH_GENERATOR_FOCAL_LENGTH = CAP_OPENNI_DEPTH_GENERATOR + CAP_PROP_OPENNI_FOCAL_LENGTH``
|
||
- ``CAP_OPENNI_DEPTH_GENERATOR_REGISTRATION = CAP_OPENNI_DEPTH_GENERATOR + CAP_PROP_OPENNI_REGISTRATION``
|
||
|
||
For more information please refer to the example of usage openni_capture.cpp_ in ``opencv/samples/cpp`` folder.
|
||
|
||
.. _openni_capture.cpp: https://github.com/Itseez/opencv/tree/master/samples/cpp/openni_capture.cpp
|