[Matplotlib-users] edit EPS

Hello,

I need your help! I have an image, saved in .eps (vector) format. 

Now the image is just a couple of plots with a legend, saved in colour, but without special tick marks to differentiate the plots. What I need to do now is *add the tick marks*. A diamond to one plot, a little cross for another etc. The original data that produced the plots is gone, I only have the .eps to work with.

I tried editing the image with PIL, but as soon as I load the image it becomes rasterized (=a small matrix of pixels, unusably ugly). 

Is there any way to edit the EPS in matplotlib? Or maybe some other, easier way to add the plot marks ex post? I am no expert on vector graphic formats.

I'm using py2.5 w/ matplotlib 1.0.0, but can install any other soft if necessary.

Many thanks!