version 8.0
Dynamic .NET TWAIN is a .NET document imaging SDK based on the TWAIN and DirectShow standards. It provides rich APIs for scanner and webcam software development.
- Install the Dynamic .NET TWAIN SDK from the download site
 - Launch Visual Studio, and create a new .NET project
 - Right-click References > Add Reference 
DynamicDotNetTWAIN.dll 
- Customizable image scanning and loading process
 - Compatible with TWAIN Specification 2.1,and backwards compatible with earlier specifications
 - Save and upload images to a local disk, FTP site, web server or database
 - Supports BMP, JPEG, PNG, TIFF, PDF, multi-page TIFF, and multi-page PDF file formats
 - WinForms & WPF controls available for most components
 - Supports WinForms (.NET Framework V2.0 SP2 and above) &WPF (.NET Framework V3.5 SP 1 and above) applications
 - Compatible with DirectShow
 - Supports .NET 32 and 64 bit
 - Supports AnyCPU (x86/x64) build
 - Barcode and OCR recognition
 - PDF Rasterizing and Annotation
 
http://www.dynamsoft.com/Downloads/.Net-TWAIN-Sample-Download.aspx
https://www.dynamsoft.com/Products/.Net-TWAIN-Scanner-License.aspx