The embedded zooming applications for personal digital assistants

Zooming technology is an essential part of personal digital assistants (PDAs) for today´s information-intensive world, which caused big problems for small screen interfaces. This paper introduces many zooming applications such as a file zoom, a focus zoom, and a search zoom which are based on geometric and semantic zooming methods. The file zooming applications use dynamic zoom-in and zoom-out functions for visualizing large amounts of information on the PDA screen. Also, users can save a file into the PDA using a zoom-out function based on a semantic zooming method; the file will gradually shrink until it appears as an icon or a small image on the screen. The focus zooming applications are built on a magnifying glass lens that is a 2D visualization for large rectangular presentations; they allow a user to quickly focus on a part of the PDA screen. In addition, we implement a blurring lens on the screen, so that users can ignore blurred objects to increase their focusing ability. The paper also describes the search zooming applications that allow for easy recognition and comparison of the content of files on the screen. Two types of viewing approaches, a popup viewing method and a shadow viewing method are introduced in this zooming method.