Hi,
I just read this article,(http://www.informit.com/articles/article.asp?p=102165&seqNum=2), and I’m unsure about the following passage:
NOTE
PNG files are by far the best for importing into Flash because Flash runs .JPG compression when you publish a movie. You don’t want to compress an image twice, so don’t import .JPG images. Seriously. Just don’t do it.
My skepticism with this advie is Macromedia appears savvy enough to anticipate this redundancy and compensate for it, please enlighten?
well, it used to be true.
not so much anymore, since Flash MX recognizes the compression, and allows the designer to either use the same compression, or a different one of thier choice.
Hope that clears up the confusion.
yeah, just check the properties of an imported image in the library and you can see what rev is talking about 
PNG’s rock because they have true blended transparency. Gif’s suck in that category. I usually import all png’s unless I HAVE to do something else.
that extra channel increases file size, though.
I mean for transparency images though. For the most part, I externally load jpgs. But for when you really need transparent and sharp imported images, pngs are the way to go.
What you can do when importing JPG filesinto Flash is to make sure you optimize them before you import them into flash and on the Flash library make sure “use imported jpeg data” is checked, that way Flash won’t compress the files twice like cki says.