[HELP] Graphics optimisation question

Can anyone here tell me how the flash graphics engine stores and processes PNG's with alpha channel if there's no alpha'd areas?

All of the tiles in our game are PNG's with alpha channel, but some tiles are flat colour with no alpha. Will the flash player spend longer calculating those graphics than if we'd exported and loaded them as flat GIFs with no alpha channel?

Does anyone have any tips on optimising tile graphics?

Thanks in advance!

r404

it think when the graphics get to the card they are all 32 bit images. flash will save your image as either jpg (even if it has alpha) or png/gif depending which is the most efficent format. [png/gif will generally store the image "as is" while jpg will generally apply a loss compression that will make the image a little blury. you can check this by double clicking the image in the library. i generally convert all my sprite/tile images to 8 bit png's with alpha transparency. with 8 bit pngs you can reduce the size quite a bit by reducing the size of the palette.

thanks for the info!