TWAIN Directory
Readme File
The contents of this directory have been collected from the TWAIN Working Group website (http://www.twain.com). Integrators are strongly encouraged to check the site for any updates. Most of the files are in PDF format, so if you don’t have Adobe Reader you can get it here (http://www.adobe.com).
This is the TWAIN 2.1 Specification, containing all the information needed to write TWAIN applications.
This is the C/C++ header file containing all the TWAIN operations and capabilities described in the specification. Users of other languages (like Visual Basic or Delphi) either need to convert this file themselves or get a copy of an appropriate definitions file from the TWAIN user community.
The TWAIN Kit contains the latest Data Source Manager (DSM) files for versions of Windows that do not have the Windows File Protection system (like Windows 98SE). It also contains the TWACKER, a diagnostic program provided by the TWAIN Working Group that can be used to exercise specific driver capabilities and operations.
TWAIN driver capabilities should be negotiated in a specific order to comply with the specification, and to increase the chance of an application working with a driver without problems. For example, an application should negotiate the color space (ICAP_PIXELTYPE) before negotiating the number of bytes per pixel in the color space (ICAP_BITDEPTH). This document goes though all the major capabilities in the standard and creates a negotiation hierarchy.
Because of its origins, TWAIN had to shake off a label of being a low-end scanner driver. TWAIN’s design is appropriate for all scanners, this document details why that is the case.
Properly constructed TWAIN drivers are expected to support certain capabilities and operations. Even though this document is geared more towards TWAIN driver writers, application writers can benefit from it as well.