Webcam preview in GUI axes is shown as black image

Hi there,

i'm trying to show the live video of a webcam in an GUI right now using the axes area.

By using the preview function in it's own window i can see the live video of the webcam.

But by using the preview function with the image handle to show the sequence in the axes area there is just a black image displayed.

I already changed the resolution and tried a different webcam, but i always get the black image.

The Webcam is a Logitech c922 Pro Stream and i'm using Windows 10 64 bit with Matlab R2019a.

Thank you very much for your help in advance.

Best

Valentin

Here is the code i'm using:

function pushbutton_start_Callback(hObject, eventdata, handles)
    cam = webcam(2);
    frame = snapshot(cam); 
    im = image(handles.axes_video,zeros(size(frame),'uint8')); 
    axis(handles.axes_video,'image');
    preview(cam,im)
end

Answer 1

[Geoff Hayes]

Valentin - please see similar question and answer at https://www.mathworks.com/matlabcentral/answers/466753-webcam-preview-in-gui-not-showing-up.

[Valentin Stegmaier]

Hi Geoff,

thanks for your help. Everything working now.

Best valentin