AS3/Flash performance with large bitmaps

i have a AS3/FL10 based application that renders/animates/filters (blur) large PNGs (1 per view) (about 1100x900 px, roughly 2mb). Due to the fact that the fans start spinning like crazy on my notebook, i wonder if this is considered "bad practise". Unfortunately i need transparent images, so JPG is not a choice. Add开发者_JS百科itionally, the PNGs are loaded dynamically, so embedding the files to the flash file (for utilizing flash jpg compression) is not a choice either.

How do you guys deal with large bitmaps in flash? Any tips?

thanks

Blur is very heavy to apply runtime, especially that you have to make Flash do a few passes (= good quality) to make it look nice with a big still image. So the somewhat obvious suggestion would be to have the blur applied on the PNG itself, or if you need it without blur too, then keeping 2 versions. I think blurred images compress quite well, so shouldn't be as big as the original.