How to run webcam on an axis in app designer ?

        function startcamerabutton_Callback(app, event)
            % hObject    handle to startcamerabutton (see GCBO)
            % eventdata  reserved - to be defined in a future version of MATLAB
            % handles    structure with handles and user data (see GUIDATA)
              app.camera=videoinput('winvideo',1);
              imshow(app.camera,'Parent',app.livedisplay);

        end

[Ahmer Shahid]

This Error showing up there.......

Error using imageDisplayValidateParams Expected input number 1, I, to be one of these types:

numeric, logical

Instead its type was videoinput.

Error in images.internal.imageDisplayValidateParams (line 11) validateattributes(common_args.CData, {'numeric','logical'},...

Error in images.internal.imageDisplayParseInputs (line 78) common_args = images.internal.imageDisplayValidateParams(common_args);

Error in imshow (line 245) images.internal.imageDisplayParseInputs({'Parent','Border','Reduce'},preparsed_varargin{:});

Answer 1

[Astarag Chattopadhyay]

Hi Ahmer,

You do not need to use "videoinput" object you can use "webcam" object.

In your app define two properties like this:

properties (Access = private)
        webcamObject;
        imageObject;
end

You can define the startup function using the following code snippet:

function startupFcn(app)
        app.webcamObject = webcam;
        app.imageObject = image(app.UIAxes);
        axis(app.UIAxes,'ij')
        res = split(app.webcamObject.Resolution,'x');
        app.UIAxes.XLim = [0,str2double(res{1})];
        app.UIAxes.YLim = [0,str2double(res{2})];
        app.webcamObject.preview(app.imageObject);
end

This will setup the UIAxis with the resolution of the webcam object and start the preview.

[Ahmer Shahid]

Yes, Its working thanks alot but there is a problem when I close the window it stucks.

Kindly help.

[Ahmer Shahid]

I also cannot get the snapshot of the webcame preview. Kindly help Thanks in advandce.

[Astarag Chattopadhyay]

Which version of MATLAB you are working on?

If you want to take a snapshot you can add a snapshot button to the app and add a callback to the button where you may use the function "snapshot".

[Ahmer Shahid]

I'm using Matlab R2018a, I'm already working on that but when I use snapshot or getsnapshot then it give me error that snapshot is invalid function for webcam.

I can use snapshot function for videoinput but I cannot get the live streaming on axis while using videoinput.