snapshot - Capture RGB image from Camera - MATLAB (original) (raw)

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Capture RGB image from Camera

Syntax

Description

[img](#mw%5Fe4b05cd3-43c2-4308-8af7-5b4bfa560604) = snapshot([cam](#mw%5F5baf409e-1a43-4ff8-b5a0-79d1d43d9c84)) returns a still image in RGB format from the camera specified in thecam object.

example

[[img](#mw%5Fe4b05cd3-43c2-4308-8af7-5b4bfa560604),[ts](#mw%5F7b1412f7-38f5-4cb4-98dd-510c308cf04b)] = snapshot([cam](#mw%5F5baf409e-1a43-4ff8-b5a0-79d1d43d9c84)) returns a still image in RGB format and the time stamp of the capture from the camera specified in the cam object.

example

Examples

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You can connect from the MATLAB® software to a USB 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('jetson-board-name','ubuntu','ubuntu');

To find the web camera name, check the webcamlist property of thehwobj object.

ans =

1×1 cell array

{'Microsoft® LifeCam Cinema(TM)'}

If this property is empty, then try reconnecting the USB webcam and run the following command. This command tries to scan the available webcams on the target when there is a addition or deletion.

updatePeripheralInfo(hwobj);

Create a webcam object, wcam using the name or the index number of the webcam list. If a webcam name or the index is not specified, then it uses the default webcam. The wcam object has the following camera properties.

wcam =

webcam with properties:

                Name: 'Microsoft® LifeCam Cinema(TM)'
          Resolution: '320x240'
AvailableResolutions: {1×12 cell}

To display the images captured from webcam in MATLAB, use the following commands.

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

To change the resolution of the image capture, use the following command.

clear wcam; wcam = webcam(hwobj,1,[1280 800])

You can use the AvailableResolutions property of thewcam object to get a cell array of the available resolutions for your camera.

Import and display a sequence of 50 snapshots on your host computer.

figure(); for ii = 1:50 img = snapshot(wcam); imagesc(img); drawnow; end

Output Arguments

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RGB image, returned as an _m_-by-_n_-by-3 numeric array with values in the range [0,255].

Data Types: uint8

Timestamp of the snapshot, returned as a datetime object.

Extended Capabilities

Version History

Introduced in R2018b

See Also

Functions

Objects

Topics