How to create a custom preview window for MATLAB webcam?

I am using the webcam function from "MATLAB Support Package for USB Webcams" to acquire images from my webcam.

The preview function creates a standalone preview window, but how can I create a preview image in a custom window or app?

Answer 1

[MathWorks Support Team]

To create a custom preview window for webcam you can use the following example as a starting point. This code creates a figure, axes, and image elements programmaticaly, but the same configuration would apply for an app created with GUIDE.

 

%%Example WEBCAM custom preview window for MATLAB R2017a

%%List connected webcams
webcamlist

%%Connect to webcam
c = webcam(1);

%%Setup preview window
fig = figure('NumberTitle', 'off', 'MenuBar', 'none');
fig.Name = 'My Camera';

ax = axes(fig);
frame = snapshot(c);
im = image(ax, zeros(size(frame), 'uint8'));
axis(ax, 'image');

%%Start preview
preview(c, im)
setappdata(fig, 'cam', c);
fig.CloseRequestFcn = @closePreviewWindow_Callback;

%%Local functions
function closePreviewWindow_Callback(obj, ~)
c = getappdata(obj, 'cam');
closePreview(c)
delete(obj)
end

 

[Andrei]

With the way webcam preview is currently working (as of MATLAB R2018a), you need to specifically assign the figure's CloseRequestFcn to a callback function which closes the figure with close(hFig) or delete(hFig) as in the example above, where hFig is the preview figure handle. If you are previewing multiple cameras in different figures, you also need to do this for the CloseRequestFcn of each of the multiple preview figures.

Answer 2

[MathWorks MATLAB Hardware Team]

You can also try using the Acquire Webcam Image MATLAB Live Task. For more details refer to the following answer https://www.mathworks.com/matlabcentral/answers/821010-how-do-i-view-the-live-video-feed-and-capture-images-from-my-usb-webcam-in-matlab