camera

Create camera object to acquire images from a USB or CSI camera attached to the NVIDIA hardware

Description

example

cam = camera(hwObj,cameraName,resolution) creates a camera object cam and connects to a camera that is attached to the NVIDIA® DRIVE or Jetson hardware. The camera function supports cameras connected to USB and camera peripheral interfaces (CSI) of the target board. When the camera object is created, it connects to the camera and establishes exclusive access to stream data. You can preview the data and acquire images by using the snapshot function.

Note

Because the software establishes exclusive access to the camera, you cannot associate more than one object to the same camera. Before code generation and execution, you must clear the camera object by using the clear function.

The CSI drivers on the NVIDIA target do not support odd pixel values for the resolution.

cam = camera(___,'VideoDevice','VideoDeviceID') creates a camera object cam and connects to a camera by using Linux® device number. If your target hardware is connected to multiple cameras with the same name, use the 'VideoDevice' argument to specify the camera to create a connection to.

Examples

collapse all

You can connect from the MATLAB® software to the onboard CSI camera connected to an NVIDIA platform and capture images from this camera.

Create a live hardware connection from the MATLAB software to the NVIDIA hardware by using the jetson function. To create a live hardware connection object, provide the host name or IP address, user name, and password of the target board. For example,

hwobj = jetson('192.168.1.15','ubuntu','ubuntu');

To find the camera name, use the getCameraList function.

camlist = getCameraList(hwobj)
camlist =

  2×3 table

             Camera Name              Video Device            Available Resolutions        
    ______________________________    _____________    ____________________________________

    "vi-output, ov5693 2-0036"        "/dev/video0"    "[1280 720],[2592 1458],[2592 1944]"
    "Microsoft LifeCam Cinema(TM)"    "/dev/video1"    "(View resolutions)"   

If the function does not list a USB based camera, try reconnecting the USB webcam and run the updatePeripheralInfo function. This function tries to scan the available webcams on the target when there is an addition or deletion.

updatePeripheralInfo(hwobj);

Create a camera object, cam using the name of the camera from the list and a supported resolution. If there are multiple cameras with the same name, use the 'VideoDevice' argument to identify a camera by its Linux device number. The cam object has the following camera properties.

cam = camera(hwobj,"vi-output, ov5693 2-0036",[2592 1944])
cam = 

  camera with properties:

           Name: 'vi-output, ov5693 2-0036'
      ImageSize: [2592 1944]
    VideoDevice: '/dev/video0'

To capture a frame of image from this camera and display it in MATLAB, use the following commands.

img = snapshot(cam);
figure();
imagesc(img);
drawnow;

To change the resolution of the image capture, you must clear the camera object by using the clear function and then use the camera function to connect to the camera again.

clear cam;
cam = camera(hwobj,"vi-output, ov5693 2-0036",[1280 720]);

Input Arguments

collapse all

Connection to a specific NVIDIA hardware board, specified as a jetson or drive object.

Use the jetson or the drive function to create this connection.

Name of the camera attached to the target hardware, specified as a string or character vector. This argument identifies a particular camera by its name. You can use the exact name that is returned by the getCameraList function, such as 'Microsoft LifeCam VX-2000'

The height and width of the image in pixels that the camera captures, specified as a 1-by-2 numeric array. Use the getCameraList function to get a list of the Available Resolutions supported by the cameras connected to the target board. You can specify height and width values that are multiples of the resolutions supported by the camera. The CSI drivers on the NVIDIA target do not support odd pixel values for the resolution.

Create a camera object by using the Linux device number of the camera, specified as a character vector. If your target hardware is connected to multiple cameras with the same name, use the 'VideoDevice' argument along with a value to identify the camera to create the connection to. Use the getCameraList function to get the Video Device number of the cameras connected to the target board.

Example: camera(hwObj,"vi-output, ov5693 2-0036",[2592 1944],'VideoDevice','/dev/video0')

Output Arguments

collapse all

Connection to a camera that is attached to the NVIDIA Drive or Jetson hardware. To capture images from the camera, use the cam object with the snapshot function.

Introduced in R2019a