WIA architecture is both an application programming interface (API) and a Device Driver Interface (DDI). The WIA architecture includes components provided by the software and hardware vendor, as well as by Microsoft. Figure 1 below illustrates the WIA architecture.
F
igure 1. The components of WIA architecture.
The main WIA architectural components are described in further detail below.
Scanner and Camera Wizard. Using the Scanner and Camera Wizard, you can retrieve images from any of the WIA-enabled devices installed on the system. The wizard provides a preview page where you can select from several scanning options and adjust image settings. It is launched by default when WIA-enabled scanners are activated (a “scan event”) and when Plug and Play still digital cameras are connected (a “connect event”). It can also be launched when media such as flash memory cards or CD-ROMs containing image files are inserted into the computer (a “media-insertion event”). Note, however, that the wizard is not launched by default for video cameras.
F
igure 2. Choose your scanning options using the Scanner and Camera Wizard.
Windows XP also gives you the option of launching a preferred imaging application for these events—rather than using the wizard by default—provided that the application is WIA-enabled.
Using the wizard for a digital still camera, you can select one or more pictures, rotate them, and view information such as picture size and resolution. With a video camera, you can select previously captured still images, rotate them, view picture information, and even see live video and capture still images. You can also name the pictures, save them in the My Pictures folder, categorize pictures by using subfolders, and publish them on the Web. For non–Plug and Play devices, you can start the wizard from the Accessories menu.
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