http://www.edaboard.com/ftopic325427.html
% Create video input object.
vid = videoinput('winvideo')
% Set video input object properties for this application.
% Note that example uses both SET method and dot notation method.
set(vid,'TriggerRepeat',Inf);
vid.FrameGrabInterval = 5;
% Set value of a video source object property.
vid_src = getselectedsource(vid);
set(vid_src,'Tag','motion detection setup');
% Create a figure window.
figure;
% Start acquiring frames.
start(vid)
% Calculate difference image and display it.
while(vid.FramesAcquired<=100) % Stop after 100 frames data = getdata(vid,2);
diff_im = imadd(data(:,:,:,1),-data(:,:,:,2));
imshow(diff_im);
end
stop(vid)
http://madan.wordpress.com/2007/03/23/image-capture-using-webcam-in-matlab/
