White text on a black background with text()

I'm having a strange problem: I'm trying to make a figure and save it as a PNG. The figure has annotations which I create with the text() function, like this:

textColor = 'white';
textBackground = 'black';
text(x, y, ...
     'my annotation', ...
     'Color', textColor, ...
     'BackgroundColor', textBackground, ...
     'HorizontalAlignment', 'Center');

When I use

   textColor = 'white';

There is white text over a black background in my MATLAB figure, but NOT in the PNG. In the PNG there is only a black box with no text. The strange part is that if I change

   textColor = 'red';

I get red text on a black background (expected) on both the figure and the PNG.

Does anyone have any idea why this is happening?

[Jan]

How do you save the PNG?

[Devin]

saveas(maphandle, ['/path/frames/frame-' imnum '.png'], 'png');

Answer 1

[Josh Porter]

I had a similar problem involving black text. If I left the text black, it would export to an EPS file as white, which meant that it couldn't be seen on a white background. (When I opened the EPS file in Illustrator, I could see that the text was actually there, just colored white.)

My solution was to set the text color to almost-almost-black:

[eps, 0, 0]

Visually, this is indistinguishable from black, but to Matlab, it is not black. This fixed the problem.

If your white is not staying white when exported, try using almost-almost white:

[1-eps, 1, 1]

It's hackish, but it works.

[Jonathan Whiting]

Very nice! This worked great!

Answer 2

[Image Analyst]

"How do I save a figure?" has got to be the most frequently asked question of any time period you want to look at. Have you tried the FAQ? http://matlab.wikia.com/wiki/FAQ#How_do_I_save_my_figure.2C_axes.2C_or_image.3F_I.27m_having_trouble_with_the_built_in_MATLAB_functions.