Saving figures with transparent patches / objects - figure background turning black

Hi,

I have an issue trying to print (or save using export_fig etc.) a plot that has some transparent patches - these are histogram bars and the transparency has been set using 'facealpha' for example

(h3,'facecolor',rgb('orange'),'facealpha',0.9);

When coming to print/save this figure, in the final saved figure the background colour is black. I've tried both the print and export_fig function to print to png but I can't get around this issue. Any ideas? Thanks.

Answer 1

[Christiaan]

Dear Sir/Madame,

Please try the following example. It makes an 3D plot, makes it transparant and saves it as a png.

clc;clear all;close all;
fig1=figure(1);
[x,y] = meshgrid([-2:.2:2]);
z = x.*exp(-x.^2-y.^2);
h1=surf(x,y,z,gradient(z));
set(h1,'facecolor','r','facealpha',0.3)
set(gca,'color','none')
print('plot','-dpng')

If you have plotted this figure, you can go in the figure GUI to edit-> copy figure. Now, if you paste this in a text programm (i.e. Word) you obtain a transperant figure also in Word.

Good luck! Christiaan

[Initial Conditions]

Hi Christiaan,

The plot looks fine in Matlab, but when I open the png file I get the same problem - a totally black figure. Your suggestion will help me get round this problem manually, but I was looking for a fix where I don't have to use the GUI.

Just out of interest, if you open plot.png outside of Matlab, do you get the same result as me - a totally black figure?