On Fri, 12 May 2006 21:44:42 +0100, John Rumm wrote:

It does not matter really, it needs decripting prior to display, you
knobble it then. (some of the PDF writer software development component
sets are quite handy for this sort of stuff, since you can render
objects one at a time and work out which ones to not bother rendering! ;-)

Yes but you've got to pay for the software ;-)

(Cue: anyone aware of any OSS that does such manipulations?)