Adobe Extending Flash Professional CS4 - Manual (Page 64)

42 EXTENDING FLASH CS4 PROFESSIONAL
BitmapItem object
Description
Property; a Boolean value that specifies whether to use the default imported JPEG quality (
true ) or not ( false ).
Available only for JPEG compression.
Example
The following code sets the
useImportedJPEGQuality property of the first item in the library of the current
document to true :
fl.getDocumentDOM().library.items[0].useImportedJPEGQuality = true;
alert(fl.getDocumentDOM().library.items[0].useImportedJPEGQuality);