closing matlab webcam automatically in matlab

I want to automatically close the webcam each time the matlab program opens. The reason is that the main gui has many functions, and if there is an error, or the user breaks out of the code, there is no way to go back and close the webcam, it is left in an open state.

with other hardware in the past, there are ways to poll the status of the device to see if it open and then, allow it to reconnect so it can be shut down cleanly.. this being done at the start of the program.. how do it do it with the webcam..

these are some of the base commands for the webcam app im using http://www.mathworks.com/help/supportpkg/usbwebcams/ug/acquire-images-from-webcams.html#bt6eea0

ideally we have the full blow instrument and data acq toolboxes, not sure why we are using this but would be nice to finish with this.

this is some base code, not the real GUI which has many functions

framerate_desired=10; % frames per second

cam1 = 'Logitech HD Webcam C615';

% cam2 = 'Integrated Webcam';

% cam3 = 'Endoscope';

bore = webcam(cam1);

bore.Resolution = '640x360';

vidWriter = VideoWriter('frames3.avi');

vidWriter.FrameRate = framerate_desired; % output framerate

open(vidWriter);

'for index = 1:30

      img = snapshot(bore);

      imwrite(img, 'test.jpg', 'jpg')

      writeVideo(vidWriter, img);

end

close(vidWriter);

clear bore

Answer 1

[Walter Roberson]

"if there is an error, or the user breaks out of the code, there is no way to go back and close the webcam, it is left in an open state."

You should use an onCleanup() to close the camera. An onCleanup() is essentially attached to an object (or variable) and is executed when the item is deleted, such as if the item is a local variable in a function that exits.

onCleanup() will also be executed if the item it is attached to is clear'd.