TWAIN SDK

GdPicture components offer superior support for image acquisition from scanners, capture cards and digital cameras using TWAIN protocol in 32-bit and 64-bit modes.

With just a few lines of code, you will be able to start a single or a multiple image acquisition process using any TWAIN-compliant device, edit and save scanned documents to any destination such as a local/network machine, FTP site, web server, or database.

Intuitive low-level & high-level API are provided under .NET components and TWAIN ActiveX to let you negotiate all TWAIN 2.3 capabilities from any kind of WinForm, WPF or Web application.

Download GdPicture.NET SDK

GdPicture.NET TWAIN SDK for Winform, WPF & Web applications development

TWAIN scanning

The acquisition process requires three items: a scanner, a driver, and software. Drivers are the bridges that let the software communicate with the device through standardized APIs. TWAIN is an industry-standard API for image acquisition, strongly oriented toward scanners. Of the four different scanning protocols, TWAIN is the most widely adopted by the market. Supported by most operating systems (Windows, Mac OS, Linux/Unix), the protocol defines a set of options like resolution, color, scanning areas for flatbed scanners, and more. The TWAIN Working Group develops and maintains TWAIN since 1992.

Main TWAIN features of the SDK

Image source enumeration and selection.
Duplex scanning support.
100% compatible with any Kofax VRS.
Handles 32-bit & 64-bit Data Sources.
Automatic Document Feeder (ADF) control.
Detect blank pages.
Number of image transfers negotiation.
Save & restore scanner configuration from file.
Image scanning attributes control, such as color-depth, resolution, brightness, contrast, size and more.
Detect & read barcode symbols, including Code 39/128/93, EAN-8/13, PostNet, PDF417, 2 of 5 Matrix and many others.
Acquire images in multiple formats, including PDF/A, PDF-OCR, encrypted PDF, Multi-page TIFF, JPEG, JPEG 2000, JBIG2, GIF, PNG and EXR.
Acquire images to an FTP or HTTP server.
Fully compatible with CITRIX systems and Windows Terminal Services*
Plus many more features that your scanner can support!

*If you have problems using CITRIX, please look at the following knowledge base articles:

Benefits

Reliable technology

API built on top of the best document imaging SDK in the market, taking benefit of more than 15 years of continuous research focused on innovation. Support for unstable TWAIN drivers thanks to continuous device diagnosing.

Reduced Time to Market

Add the advanced post processing features provided by the GdPicture.NET toolkit to your scanning application: PDF, OCR, formats conversion & document imaging SDK. Reduce the learning curve by using the same technology on different platforms.

Continuous Development and Delivery

To provide you with the latest technologies and an always up-to-date SDK, we publish weekly releases. Check our version history page and subscribe to our developer newsletter to learn more about the new features and improvements.

Universal scanning SDK

GdPicture.NET scanning SDK is compatible with the two most used scanning protocols, TWAIN and WIA. Acquisition from all types of scanner devices and digital cameras is possible with support for both 32 and 64bits.

Web scanning SDK with DocuVieware

TWAIN acquisition via the dedicated scanning snap-in. 0 configuration required.
TWAIN acquisition via the dialog window triggered by a dedicated toolbar button.
High & low-level API sets to customize any acquisition process entirely.
Communicate with 32-bit & 64-bit TWAIN devices.
All acquisition options are supported via the device driver user interface or using a dedicated TWAIN JavaScript API.
Adaptive compression mechanism.
High-volume document scanning.

Support for any transfer mode of the TWAIN specification that automatically selects the version with the best user experience based on the system resources available.
Save scanned documents as PDF/A or TIFF images by default.
Advanced document clean-up features.
Working flawlessly with all Windows browsers.
Preview scanned pages with intuitive zooming, rotating & page reorganizing tools.
Support for low bandwidth with fault-tolerance mechanisms.

How to use the live demo?

TWAIN acquisition can be made from the dedicated snap-in or a dialog window triggered by a dedicated toolbar button.

When launching DocuVieware for the first time, the viewer will require the installation of a small software to connect to the TWAIN devices. It is a one-time step, and once it has been installed, it is silently started with Windows.

DocuVieware will then be able to trigger the device driver window so you can choose the acquisition settings you need.

Learn more about TWAIN web-scanning on the DocuVieware website.

FAQ

When should I used WIA over TWAIN?

WIA (Microsoft Windows Image Acquisition) API is standardized for acquiring digital images from devices that are primarily used to capture still images and for managing these devices. WIA is a COM interface, very different from but overlapping with TWAIN.

Compared to TWAIN, WIA offers much better support for digital cameras and much less sophisticated support for scanners.

There are a few other parameters to keep in mind:

support for scanners with ADF (Automatic Document Feeder) is much more robust with TWAIN.
WIA uses a common dialog for all devices.
TWAIN uses a dialog created by the device manufacturer, providing more options and custom capabilities for each device.
TWAIN has three transfer modes (Native, Memory, File) while WIA has two (Memory, File).
Most TWAIN sources save the settings of the previous scan, while WIA does not.
Duplex scanning mode offers better support in TWAIN (each side can be saved with different options) with WIA using the same settings for both sides.

Check our WIA scanning page for more features and functionalities.

Are there other scanning protocols?

There are four scanning protocols currently used by the market:

TWAIN
WIA (Microsoft Windows Image Acquisition)
ISIS (Image and Scanner Interface Specification)
SANE (Scanner Access Now Easy)

Here is a chart that synthesizes the different features of each protocol:

	TWAIN	WIA	ISIS	SANE
Adoption by the market	very high	high	low	low
Developed by	TWAIN Working Group	Microsoft	Pixel Translations (then EMC Corporation’s Captiva Software). Now owned by OpenText	SANE open-source project
Digital camera support	high	very high	low	very low
Supported OS	Windows, Mac OS, Linux/Unix	Windows	Windows	Linux/Unix
Licensing	LGPL (Data Source Manager only) – free	proprietary – free	proprietary – commercial	open source
Specification	TWAIN specification	WIA specification	ISIS specification	SANE specification

I want to test your library, but I don’t have a scanner

If you don’t have a physical TWAIN scanner to test the SDK, you can download and use a virtual scanner (32 & 64-bit) here.

Example of usage

Asynchronous TWAIN Scanning from VB.NET and C# application.

Generating a searchable PDF from a scanner in .NET.

Acquiring an image from a TWAIN device and reading barcodes.

Creating a multipage TIFF file from a document in the scanner using the TWAIN protocol using VB.NET or C#.

Creating multipage searchable PDF (PDF/A 1.4) from the content of the document feeder of a scanner using VB.NET or C#.

HTML5 Document Viewer with TWAIN acquisition

How to use

Download and install GdPicture.NET package from here.

You will be able to find a compiled demo application in
[Install directory] \Samples\Bin\PaperScan.exe
You will be able to find C# and VB.NET demo applications including source code in
[Install directory] \Samples\WinForm\ (see TWAIN Scanning app.).
You will find other code snippets within the online reference guide found here GdPicture.NET Guides
You can find some discussions about TWAIN in the dedicated section of our community forums.

Check our other Scanning technologies

Universal Scanning Support

WIA Scanning

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