Unwanted figure transparency in Windows 7

I am generating and saving lots of plots with the following saving method:

set(gcf,'Color','w')
I = getframe(gcf);
imwrite(I.cdata, [printname,'.jpg']);

Most of the graphs are opaque but some are semi-transparent. I think this has happened since switching to Windows 7 from XP. How can I stop them becoming transparent?

Answer 1

[Matt Fig]

It might help if you set the renderer to zbuffers.

set(gcf,'render','zbuffers')

But if you have any transparent graphics objects this will destroy the transparency of those objects.

[Simon]

Great, that works, thanks.

Answer 2

[Jan]

It is not Windows 7 but the responsibility of Java for rendering the figures. This problem can be fixed by inserting a pause(0.02) before getframe(). Unfortunately this is not documented. drawnow should do this also according to the documentation, but it is not enough to let Java process its event dispatch thread. If 0.02 seconds are enough even under extrem system load is not known. Therefore I check the picture manually for "dropouts" afterwards. For the creation of a 30 minute animation movie this is hilariously silly.

@TMW: The collaboration between getframe, drawnow and Java is suboptimal, to say it friendly.