Save figure without plotting - Ubuntu specific

Hello,

I am running a batch script to `imagesc` some matrices and I want to save the figures without them showing up on the screen. I am doing:

h=figure('Visible','Off');
dlmwrite('sk_vmat_col1.txt',sk_Vmat1,'delimiter','\t','precision','%.8f');
imagesc(sk_Vmat1)
title('Skew symmetric matrix from first column of U in U,D,V=svd(C)', 'FontSize',16)
box on
saveas(h,'sk_Vmat1','png')
close

But the images still show on the screen, albeit very briefly, (super annoying thou). I think this is a Ubuntu specific problem with R2016a. When I run the same thing on a MacOS the images do not show up.

Does anyone know a work around?