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Windows Image Acquisition (WIA) is a driver model and application programming interface (API) for modern Microsoft Windows operating systems that enables graphics software to communicate with imaging hardware such as scanners, digital cameras and Digital Video-equipment. It was first introduced in 2000 as part of Windows Me, and continues to be the standard imaging device and API model through successive Windows versions. It is implemented as an on-demand service in Windows XP and later Windows operating systems.

Contents 1 Overview 2 Additional information 3 See also 4 References 5 External links

WIA is a significant super-set of the support for digital still imaging that was provided by the Still Image Architecture (STI) in Windows 2000. Whereas STI only provided a low-level interface for doing basic transfers of data to and from the device (as well as the invocation of an image scan process on the Windows machine through the external device), WIA provides a framework through which devices can present its unique capabilities to the operating system, and applications could programmatically take advantage of those features.

In comparison to TWAIN, WIA is said to be more flexible, because it is a standardized interface that doesn't require a tight bundling of scanner software and driver (TWAIN-only scanners are often limited to functions that are enabled in its driver-software-bundle). Most recent scanners support WIA.

In 2002, Microsoft released the Windows Image Acquisition Automation Library Tool, which provides access to WIA functionality through programming languages and scripting environments that support OLE Automation.

In Windows XP, WIA runs in the LocalSystem context. Because of the security ramifications of running a service as LocalSystem whereby a buggy driver or malicious person would have unrestricted access to the system, the WIA service in Windows Server 2003 and Windows Vista operates in the LocalService context. This can result in compatibility issues when using a driver designed for Windows XP.^[1]

Windows Vista additionally includes a new Picture Acquisition framework for acquiring images from imaging devices.

• Image and Scanner Interface Specification (ISIS)
• Standard for image acquisition devices (TWAIN)
• Scanner Access Now Easy (SANE)

1. ^ Microsoft published a paper in 2003 titled Security-related Best Practices for WIA Driver Development to assist WIA driver developers in writing drivers that will work in the lower-security context that the WIA service operates in.

• List of Scanners That Are Supported by Windows Image Acquisition
• Windows Image Acquisition (WIA) 1.0
• Still Image Connectivity for Windows — describes WIA and compares it to Picture Transfer Protocol and USB Mass Storage methods for transferring images between a digital imaging devices and the computer.