Hi,
seems like an openGL issue. Changing the renderer to painters or zbuffer or opengl software works:
c_H=figure;
H_axes=axes('parent',c_H);
Z= hadamard(20);
figure(c_H)
pcolor(Z)
%set(c_H,'Renderer','painters') %or
%opengl software %or
set(c_H,'renderer','zbuffer')
pause(1)
f = getframe(H_axes);
figure,image(f.cdata)
