[pstricks] Producing good PNG files

[B.D. Hall]

I am sure there has to be a way to do this well, but 2 days of 
mucking around have not solved my problem. I am looking for some advice please.

I have plenty of drawings that have been developed using PSTricks. 
Now someone has asked me contribute to a Mediawiki site and I need to 
transform some of these into a .png format (or other format accepted 
by mediawiki, like jpeg).

I have not been able to transfom PostScript or PDF versions of my 
figures into .png without quite a lot of degradation in their 
appearance. (I have used things like Gimp, GSView, and ImageMagick 
but nothing has really done the trick). It seems that the rasterizing 
of the ps or pdf information is not very satisfactory (but I'm just guessing).

I have used LatexDraw to construct many of the figures and I have to 
say that that program can export to a PNG file that looks OK. 
However, if I use any LaTeX math symbols in the drawing then they are 
not handled by the exporting software. (I assume therefore that what 
is exported is not really derived from PSTricks in this case).

So my question is this: can anyone advise me on how to produce 
reasonable png files from my existing PSTricks / LaTeX sources? It 
has to be possible, I say to myself, because I can see all these nice 
figures on PSTrick's page on Wikipedia!

Thanks in advance

Blair