Convert Bitmap Images to Symbols in Flash CS5
When a bitmap image is on the Adobe Flash Creative Suite 5 stage or in the library, it can be converted to a symbol just like any other graphic on the Flash CS5 stage. The process is the same, and the image inherits the same abilities that graphic symbols do, including tween ability, tint, transparency, and management from a master symbol in the library.
Follow these steps to convert a bitmap image to a symbol:
Choose an imported bitmap image from the library and drag the image to the stage.
If you already have a bitmap on the stage, select it with the Selection tool.
Choose Modify→Convert to Symbol.
The Convert to Symbol dialog box appears.
Enter a name in the Name text box, choose Graphic from the Type drop-down list, and set the registration point using the grid.
You can also convert bitmaps to buttons or movie clips by choosing Button or Movie Clip from the Type drop-down list.
Click OK to complete the conversion.
The bitmap image appears as a new graphic symbol in your library. You can now drag several instances to the stage and then tween and transform it.
Symbols created from imported bitmaps create dependencies and continue to reference the original raw bitmaps in the library. Deleting raw bitmap assets from the library causes them to disappear from any symbols that use them.