Why is saveas() changing my image aspect ratio?

I'm trying to save a figure as a PNG but the aspect ratio changes for some reason.

This is how it looks in MATLAB:

This is how it looks when I save it (slightly elongated as you can see):

How can I fix this?

g = figure;
subplot(1,2,1)
imagesc(im1);
subplot(1,2,2)
imagesc(im2);

g.WindowState = 'maximized'; % this didn't work  
saveas(g, name, "png");

Answer 1

[Jan]

Try to set the 'PaperSize' property of the figure.

Answer 2

[Eamon Gekakis]

The exportgraphics function may be useful here, 'Resolution' is available as a name-value pair input argument.

[Researcher]

This doesn't change size though, only resolution.