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snapshot

Capture latest RGB image frame from camera

Description

example

img = snapshot(mycamera) returns the latest still image frame from the Camera Board in RGB format.

img = snapshot(wcam) returns the latest still image frame from the USB web camera in RGB format.

Examples

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You can connect to the camera board on the Raspberry Pi hardware, from the MATLAB® software, take a photograph, and record video.

Create a connection from the MATLAB software to the Raspberry Pi™ hardware.

mypi = raspi

Create a connection, mycam, from the MATLAB software to the camera board on the Raspberry Pi hardware, and set the image resolution. The connection displays the camera board properties.

mycam = cameraboard(mypi,'Resolution','1280x720')
mycam = 

Cameraboard with Properties:

                    Name: Camera Board   
              Resolution: '1280x720'       (View available resolutions)
                 Quality: 10              (1 to 100)
                Rotation: 0               (0, 90, 180 or 270)
          HorizontalFlip: 0              
            VerticalFlip: 0              
               FrameRate: 30              (2 to 30)
               Recording: 0              

   Picture Settings
              Brightness: 50              (0 to 100)
                Contrast: 0               (-100 to 100)
              Saturation: 0               (-100 to 100)
               Sharpness: 0               (-100 to 100)

   Exposure and AWB
            ExposureMode: 'auto'          (View available exposure modes)
    ExposureCompensation: 0               (-10 to 10)
                 AWBMode: 'auto'          (View available AWB modes)
            MeteringMode: 'average'       (View available metering modes)

   Effects
             ImageEffect: 'none'          (View available image effects)
      VideoStabilization: 'off'          
                     ROI: [0.00 0.00 1.00 1.00] (0.0 to 1.0 [top, left, width, height])

Capture and display a sequence of 10 snapshots on your computer.

for ii = 1:10
img = snapshot(mycam)
    imagesc(img)
    drawnow
end

Each of the 10 snapshots is the latest image captured by the camera.

If the image is upside down, change its orientation.

mycam.Rotation = 180

You can use the same approach to change the values of other cameraboard properties.

Record a 60 second video.

record(mycam,'myvideo.h264',60)

Stop the recording immediately.

stop(mycam)

Copy the video from the board to your computer.

getFile(mypi,'myvideo.h264','C:\MATLAB ')

Delete the video file from the hardware to free up space.

deleteFile(mypi,'myvideo.h264')

You can connect from the MATLAB software to the USB web camera connected to Raspberry Pi board and take a photograph.

Connect the Raspberry Pi to your host computer.

Note

If you have not previously configured your Raspberry Pi, see Install Support for Raspberry Pi Hardware.

Create a connection from the MATLAB software to the Raspberry Pi hardware.

mypi = raspi

Create a connection, wcam, from the MATLAB software to the USB web camera connected to the Raspberry Pi board, and set the image resolution. The connection displays the web camera properties.

wcam = webcam(mypi)
wcam = 

  webcam with properties:

                    Name: '/dev/video0'
              Resolution: '320x240'
    AvailableResolutions: {'320x240'  '640x480'}

Import and display a sequence of 10 snapshots on your host computer.

for ii = 1:10
    img = snapshot(wcam)
    imagesc(img)
    drawnow
end

Input Arguments

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Connection to a Camera Board, specified as a cameraboard object.

Use the cameraboard function to create this connection.

Example: mycam

Connection to a USB Webcam, specified as a webcam object.

Use the webcam function to create this connection.

Example: mycam

Output Arguments

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Latest RGB image, returned as an n-by-n-by-3 matrix of values.

Extended Capabilities