Even though devices support complicated animations and 3D images, they consume processing power. If an application uses a lot of resources, keep the graphics as light as possible and maintain a balance between nice graphics and resource consumption. Consider the different graphics formats that are available and optimize the image size. Also, consider which graphics are necessary for the application, and which can be removed if performance is negatively affected. You can also set an image as the widget background.
For more information on using images, see Graphics.
For more information on incorporating different image types, see:
For more information about optimizing image size for mobile devices, see Using graphics and scripting effectively.