Can System Objects be used with webcam video acquisition for live video
Can System Objects be used with webcam video acquisition for live video in Video and Image Processing Blockset 3.0 (R2010a)? I would like to have a live video that is captured by a webcam as an input to my system object: reader = video.MultimediaFileReader This means that whatever is captured by webcam will be instantly be read by system objects for further stream processing.
John Michell answered .
2025-11-20
% Demo code below:
% -----------
%% Initialization
hCamera = videoinput('winvideo',1);
triggerconfig(hCamera, 'manual');
%
hSingle = video.ImageDataTypeConverter;
hCSC = video.ColorSpaceConverter('Conversion', 'YCbCr to RGB');
hOF = video.OpticalFlow('OutputValue', 'Horizontal and vertical components in complex form', ...
'ReferenceFrameDelay', 1);
hMean1 = video.Mean;
hMean2 = video.Mean('RunningMean', true);
hMedianFilt = video.MedianFilter2D;
hClose = video.MorphologicalClose('Neighborhood', strel('line',5,45));
hErode = video.MorphologicalErode('Neighborhood', strel('square',2));
hVideo1 = video.VideoPlayer('WindowCaption', 'Original Video');
hVideo1.WindowPosition = [50 250 350 300];
hVideo2 = video.VideoPlayer('WindowCaption', 'Results');
hVideo2.WindowPosition = [475 250 350 300];
%%
i=0;
start(hCamera)
while i < 150 % A hack to limit the demo to 150 frames
image = getsnapshot(hCamera);
I = step(hSingle,image);
Irgb = step(hCSC, I);
of = step(hOF, I(:,:,1));
of_mag = of .* conj(of);
vel_th = 0.50 * step(hMean2, step(hMean1, of_mag));
filteredout = step(hMedianFilt, of_mag >= vel_th);
th_image = step(hClose, step(hErode, filteredout));
step(hVideo1, Irgb); % Display Original Video
step(hVideo2, th_image); % Display Moving Objects
i = i+ 1;
end
%%
stop(hCamera);
%%
close('all','force');