MACROMEDIA FLASH MX 2004 - FLASH LITE AUTHORING GUIDELINES FOR THE I-MODE SERVICE Manuallines page 12

Using bitmaps
Although some i-mode phones may have more than 16 bits of color resolution, Macromedia
recommends optimizing bitmaps to 16 bits before importing them into Flash MX Professional
2004. Doing so reduces Flash Lite movie size and gives you more control over the final output.
Also, make sure that bitmaps are imported at the size they need to be in the Flash Lite movie.
Using larger than required bitmaps results in higher run-time memory requirements.
Bitmaps versus vectors
Flash Lite generally uses vectors to define content, which can tax a phone's CPU when rendering
complex graphics and animations. In general, the more vectors that are manipulated on the stage,
the more CPU power is required. This is also true for Flash movies delivered on desktop
machines. However, i-mode phones are far less powerful than desktop machines and more care
should be taken to avoid taxing the CPU.
When creating content for i-mode phones, it is sometimes better to use bitmaps instead of vectors
because they require less CPU power to animate. For example, a road map of a large city would
have too many complex shapes to scroll and animate well on an i-mode phone if it were created as
a vector graphic; a bitmap would work much better.
Using bitmaps produces larger files, so take care during development to find the right balance of
CPU versus file size and run-time memory requirements. Because of mobile phones' smaller
screens, slower data transmission speeds, limited memory and CPU speeds, developers should
take extra care in planning and testing.
If you are using bitmaps, you can set image compression options that will reduce your SWF
file size.
To set bitmap image compression:
Select a bitmap in the Library window.
1
Right-click (Windows) or Control-click (Macintosh) the bitmap's icon in the Library window.
2
Choose Properties from the options menu. The Bitmap Properties dialog box appears:
3
Select Photo (JPEG) in the Compression pop-up menu for images with complex color or
tonal variations, such as photographs or images with gradient fills. This option produces a
JPEG format file.
12 Chapter 2: Developing Content