how to take pictures from webcam connected from phone on matlab

i have a video connected webcam from phone as follows. so how can i capture images directly from them

url = 'http://192.168.2.6:8080/shot.jpg';
    ss = imread(url);
    fh = image(ss);
    while(1)
        ss = imread(url);
        set(fh,'CData',ss);
        drawnow;
    end
try
    info = imaqhwinfo;
catch 
    errordlg('Webcam aquisition not supported.')
    return
end

Answer 1

[Adam Danz]

Use exportgraphics to capture the image within your axes.

[Sang]

is that you, I don't quite understand

[Adam Danz]

Assuming ax is your axes, the line below saves the axes as jpg file. See the link in my answer for more info.

exportgraphics(ax,'myImage.jpg')

[DGM]

If you had an image, it should be able to be saved directly using

imwrite(ss,'outputimg.jpg')

instead of trying to capture the axes. That should be faster and preserve the image geometry.

Disclosure, I don't have exportgraphics(), so I can't test the exact behavior with defaults().

[Adam Danz]

If there cases where exportgraphics distorts image geometry, I'd like to be aware of them. imwrite is another good option, thanks @DGM.

[DGM]

I wouldn't say "distorts", but if it behaves like print() or saveas(), then the output geometry will be a function of figure geometry instead of strictly being equal to the image geometry, (e.g. with any added padding, etc)

hi = imshow('peppers.png'); % [384 512]

% use print
print('useprint.png','-dpng')
S = imfinfo('useprint.png');
[S.Height S.Width]

ans = 1×2

656 874

% use saveas
saveas(gca,'usesaveas.png')
S = imfinfo('usesaveas.png');
[S.Height S.Width]

ans = 1×2

656 874

% use exportgraphics
saveas(hi,'useexpg.png') % try to use the image object itself

S = imfinfo('useexpg.png');
[S.Height S.Width]

ans = 1×2

656 874

I'm sure there are ways around this, but I don't see the point in pursuing the hazard if the source image was available in the first place.