How do I make round 'o' markers render as round when saving to png

When I export a figure to an image (png or tif), the round markers form peculiar cross shapes as attached.

This happens whether using export_fig

 export_fig f1 savefig.png '-r600' -nocrop

or exporting manually via the dialogue box.

File>Export Setup> Properties/Rendering > 600 dpi Export

I'm using Matlab 2015a on Windows 7.

How do I make round 'o' markers render as round?

Thanks

Answer 1

[Mike Garrity]

That looks like an issue that the OpenGL driver has on some graphics cards when drawing wide lines. If so, you have a couple of options. Here are a few:

• The simplest is to disable the edges and just use the fill color of the markers:

plot(randn(1,120),'o','MarkerFaceColor','black','MarkerEdgeColor','none')

• Another option would be to tell export_fig to use the painters renderer.
• Starting MATLAB with -softwareopengl might help, but I think that the Microsoft OpenGL implementation in Windows 7 is one of the ones that has this issue. Perhaps you're already getting that one. What does "opengl info" report?

Answer 2

[JvBSherwood]

Hi Mike, thanks for the suggestions. The painters renderer did not work, but removing the edges did, so problem solved for now. Cheers