About the TWAIN Standard

TWAIN was developed by a consortium of software and hardware manufacturers to standardize the communication between software applications and image acquisition devices. The interface is optimized for acquisition of graphic images. The TWAIN standard is widely supported by scanner manufacturers, with the widely used version of TWAIN being 1.9 (as of this writing). In addition to scanners, TWAIN is being used with digital cameras and video capture boards. ImageGear supports all three TWAIN Transfer Modes: Native Data Transfer Mode (which is the TWAIN default), Disk File Transfer, and Buffered Memory.

A TWAIN-compliant image acquisition device is one whose device driver complies with TWAIN specification. The device driver understands the TWAIN protocol, thus allowing interaction with the Data Source Manager, the main interface module of the TWAIN software. The Data Source Manager "manages the session" between the application program and the raster-generating data source. Three software elements work together in TWAIN: the application, the Data Source (DS), and the Data Source Manager (DSM) as shown below:

This section uses the following terminology when discussing ImageGear scanning functionality:

Data Source: This is a shortened reference to the device driver of an Image Acquisition Device and will be used frequently.
Data Source Manager: The TWAIN manager for the device drivers.
Image Acquisition Device: This term covers all devices that acquire images using the TWAIN protocol, including scanners.
Scanner: This word is sometimes used as an alternative for "Data Source" when the discussion is specific to scanners but is not relevant to all Image Acquisition Devices, or "Data Sources".
Scanning: This term refers in a general sense to all methods of TWAIN image acquisition. See the TWAIN Scanning Capabilities section for details.