does anyone know how to convert a true color bufferedImage to a 256 bufferedImage?

[Simplesmile]

Hi guys,
I was wondering if anyone could help me.
I am trying to convert a bufferedImage from true color to 256. I managed to do this by using the graphic class but the problem with doing that is that the graphic class is a higher level java class so its really slow and speed is everything for the purpose of my program. Hence, does anyone know of another lower level method that could get the job done? Or, does anyone know how to mathematically round off the true color pixel to a 8-bit pixel?
my ultimate goal is to create a 256 png but there is no way to do that with the standard java library (as of my knowledge. ) so I opted to take the bufferedimage route.

Any suggestions or help would be greatly appreciated.

Thank you in advance,

[graviton]

perhaps having a look at the advanced imaging api of java can help:
http://java.sun.com/products/java-me...faq.html#10to8