Using OpenCV Grabber with YARP

[apaikan]

Using OpenCV Grabber with YARP

This is a quick tutorial of how to use Yarp opencv_grabber to

1. Capture image for your webcam and play on a YARP port
2. Play a video file on a YARP port
3. Play a images sequence on a YARP port

Enable opencv_grabber device in YARP

$ cd yarp/build
$ cmake -DCREATE_DEVICE_LIBRARY_MODULES=ON  -D=ENABLE_yarpmod_opencv_grabber=ON ../
$ make 

The opencv_grabber device options

• --name <value> set the output port name (default is /grabber)
• --camera <value> set the number of the capture device (e.g. 0, for the first camera)
• --movie <value> set the name of the video/image sequence files instead of camera for capturing
• --framerate <value> set the desired frame rate
• --width <value> set the width of the image
• --height <value> set the height of the image
• --loop enable image looping when capturing from video/image sequence files
• --flip_x, flip the image along the x-axis
• --flip_y, if present, flip the image along the y-axis
• --transpose rotate the image along of 90 degrees

Example 1: Capturing from camera (default camera frame size and rate)

$ yarpdev --device opencv_grabber --name /image:o --camera 0 

Example 2: Capturing from a video file (avi, mp4, ..)

$ yarpdev --device opencv_grabber --movie myfile.avi --framerate 30 --loop

Example 3: Capturing from images sequence (e.g., yarpdatadumper)

$ yarpdev --device opencv_grabber  --framerate 30 --movie %8d.ppm --loop

[towardthesea]

Should we mention this tutorial as a temporary solution for python with yarpdataplayer 😃