Minimizing raster zoom jitter?

One of the animation projects I'm working on has painted raster backgrounds (which I realize aren't Flash's strong suit, but I'm going for a certain look). Occasionally, I want to zoom in on one of the backgrounds and I get the standard raster jitter. Anybody have any techniques for minimizing the jitters in this situation? So far all I've come up with is 1) don't zoom unless I "have to" and 2) if I have to, do it very slowly and keep the overall percentage of zoom to a minimum. Is there anything else?

Thanks,

Matt

You could make the original image bigger and start at 50%.
If sharpness isn't important you can use a blur filter to soften the image a bit.

w.brants,

Thanks for the reply. I am in fact utilizing the "start with a bigger image" approach.

So far, the thing that seems to help the most - and I stress "seems' - is the presence of at least some vector image in the scene being zoomed. I did some A/B comparisons of painted backgrounds alone versus painted backgrounds with a vector shape and the ones that had a vector shape floating somewhere in the scene always appeared to have less jitter during a zoom than their raster-only counterparts. In fact, it cut the jitter down to a perfectly acceptable level. If that approach keeps working, it's a reasonable solution for me since I can always come up with at least one element in a scene that can be represented with a vector shape. And more often than not, there'll be a fair amount of vector shapes in the scene (in the form of characters, for instance).

Matt