Dynamic Web TWAINRelease Notes

Scanner Core Module
  • Scanner Core Module
  • Optional Addon Modules
How to Upgrade?

16.1.1 (08/13/2020)


  • Whether to load the WASM for the Camera module is now optional (used to be mandatory in 16.1) and is disabled by default.
  • The webcam/camera license is now considered a core license and can be used without a scan license.

16.1 (08/04/2020)


  • Added method SetProductKeyAsync() which sets the product key asynchronously. Previously, the property ProductKey was used for both setting and reading the key. The same behavior is kept in 16.1 but the recommendation now is to use the method SetProductKeyAsync() to set it and use the property ProductKey to read it.
  • Added methods GetSourceNamesAsync(), SelectSourceAsync(), SelectSourceByIndexAsync(), OpenSourceAsync(), CloseSourceAsync(), OpenSourceManagerAsync(), CloseSourceManagerAsync(),as asynchronous complements to their existing synchronous methods.
  • Support showing both 64-bit TWAIN drivers and 32-bit TWAIN drivers at the same time.
    • NOTE: This driver type does not work if we call SelectSource() synchronously (without callbacks).
  • Added APIs under Addon.Camera as a complement to the existing APIs under Addon.Webcam. These APIs include getSourceList(), selectSource(), getCurrentSource(), closeSource(), getResolution(), setResolution(), getCurrentResolution(), play(), pause(), resume(), stop(), getStatus() and capture(). Unlike the old APIs under Addon.Webcam which are good only on Windows, the new APIs are good on Windows, macOS, Linux as well as iOS & Android.
  • Added built-in video processing feature which enables video streaming, edge detection, perspective adjustment, capturing, etc. Related APIs include showVideo(), closeVideo() and two callbacks video-closed and video-error.
    • NOTE: on desktop, this feature requires a webcam/camera addon license.


  • Added a feature to run Dynamsoft Service with the account "Local Service". By default, it is still "Local System". Contact Dynamsoft to learn more.


  • 16.1 now supports acquiring images from a remote scanner which is connected to a machine which is connected via HTTP. This feature is designed to enable document scanning on mobile devices.


  • Improved the speed to initialize the library under WASM mode by splitting one WebAssembly file into multiple files and loading them in the background.
  • Improved memory usage by sharing the same heap among multiple WebAssembly workers.
  • Improved image decoding by removing unnecessary image processing operations as well as lowering the memory usage.
  • Improved data transferring efficiency by using pointers instead of strings.
  • Improved performance by saving compiled WebAssembly code into the working process for later use.


  • This version is backward compatible with version 16.0. This means once you have installed the Dynamsoft Service for version 16.1, an application running version 16.0 also works without the need to install the Service for version 16.0.
  • The method LoadImageEx() now supports mobile platforms as well.
  • Dynamsoft Service directory is now named with its version in it. For example, /DynamsoftServicex64/ is now /DynamsoftServicex64_16/. Also ActiveX related files are put into a different directory called /WebTWAINActiveX/.


  • Fixed a bug where images fail to show in the viewer in IE 10.
  • Fixed a bug in Chrome where the print UI invoked by the API Print() disappears immediately after showing up.
  • Fixed a bug with the API Dynamsoft.WebTwainEnv.Host which is now effective.
  • Fixed a bug with consecutive cropping operations with the API Crop().
  • Fixed a bug with WebTwain instances created by the API Dynamsoft.WebTwainEnv.CreateDWTObjectEx() so that their UI binding works correctly.


  • No deprecation in version 16.1.

Changes about the ActiveX edition

  • No changes in version 16.1.

Previous Changes >>

It is a light-weighted PDF library working with Dynamic Web TWAIN SDK on the client side to convert text-based PDF files into images and display in the image viewer. (6/18/2020)


  • This addon now works both in the Local-Service mode and the WASM mode.
  • This addon now works on iOS, iPadOS & Android too. (06/27/2019)


  • [HTML5 | Windows] Changed the old DLL names to reflect the fact that they only work as the rasterizer.
  • [HTML5 | Windows] Removed the old PDF.Download method.
  • [HTML5 | Windows] Removed license limitation on the method IsTextBasedPDF so that it can always be used regardless of whether a license is in place. (9/06/2018)


  • Added the version number of the library to the name of the library so that different versions of the library can co-exist.
  • Added a method IsModuleInstalled() to detect whether the library has been installed on the client machine.
  • Updated the library to version which is more stable and uses the memory more efficiently. The new library also has fixed a bug where a loaded PDF may appear tilted. (7/17/2018)


  • Fixed the typo EnumDWT_ConverMode to EnumDWT_ConvertMode

10.2 (1/16/2018)


  • Upgraded the current PDF Rasterizer engine for Windows client.


  • Added support for macOS client and Linux client.

9.6 (03/01/2016)


  • Added PDF Rasterizer Add-on to convert text-based PDF files to images. This way, text PDF files can be successfully displayed in the viewer of the Dynamic Web TWAIN Scanner Core module.
  • Available APIs are:
    • Addon.PDF.SetConvertMode: to turn on or off the PDF rasterizer feature.
    • Addon.PDF.Download: to deploy the PDF library from the server side to the client machine.
    • Addon.PDF.SetPassword: set the password to decrypt the targeted PDF file.
    • Addon.PDF.SetResolution: to set the output image resolution.
    • Addon.PDF.IsTextBasedPDF: to detect if a PDF file is text-based or not.

A professional linear & 2D barcode reading library for recognizing barcode from any document captured from scanners, cameras or file systems. (6/18/2020)

  • This addon has been redesigned with brand-new APIs.
  • This addon now works both in the Local-Service mode and the WASM mode.
  • This addon now works on iOS, iPadOS & Android too.

7.3 (01/07/2020)

  • Updated the library to version 7.3.
  • Removed independent service checking logic.

7.1 (09/19/2019)

  • Updated the library to version 7.1.

7.0 (08/13/2019)

  • Updated the library to version 7.0.

6.5.2 (06/27/2019)

  • Updated the library to version 6.5.2.

6.4.1 (01/15/2019)

  • Expanded the Barcode Reader feature to the ActiveX.
  • Updated the Barcode reader libraries to version 6.4.1.

6.3 (09/18/2018) (Since DWT 14.1)

5.2 (09/18/2017)


  • Improved the localization and recognition algorithms for PDF417 barcodes.
  • Optimized the de-blur algorithm for 1D barcodes to improve the recognition accuracy.
  • Optimized the timeout support. Now it is possible to stop barcode recognition by timeout.
  • Increased QR Code and DataMatrix barcode recognition speed for B&W images.

5.1 (06/20/2017) (since DWT 13.0)


  • Reconstructed the barcode reader SDKs to closely working with the Scanner Core module of the Dynamic Web TWAIN SDK.
  • Added support for reading barcodes from a base64 string image.
  • New de-blur algorithm for 1D barcodes to improve the accuracy when scanning linear barcodes from out-of-focus, blurred images.
  • Added new APIs that enable you to specify page numbers, barcode regions and barcode angles for barcode detection. These greatly improve the decoding workflow and barcode reading efficiency.
  • Added ImageCaptureDevice API to set the capture device (scanner, camera or fax) being used to scan barcode images. When set, it will use a better and more appropriate image processing technique to the images captured from that device.
  • Added BarcodeColorMode API to set the ink color for barcodes searching.
  • Added BarcodeTextEncoding API to set barcode text encoding mode so that you can display special characters properly.
  • Added TimeoutPerPage API to set the maximum amount of time for reading barcodes on one page.
  • Added Angle property to return the rotation angle of a detected barcode.


  • Updated barcode reader library with improved positioning algorithm that can better identify and locate DataMatrix barcodes.

4.3 (10/13/2016) (DWT12.1~12.3.1)


  • New localization algorithm was implemented for 1D barcode scanning to improve barcode reading speed.
  • New multi-thread processing was implemented for 2D barcode reading to improve decoding accuracy.


  • Improved recognition for perspective QR Codes.
  • Optimized decoding performance for large size, special angle and multiple 1D barcodes.
  • Other small fixes and tweaks.

4.2 (04/08/2016) (DWT12.0)


  • Changed 1D barcode decoding module to improve recognition accuracy.

4.1 (01/21/2016) (11.3~11.3.2)


  • Improved positioning algorithm to better identify and localize DataMatrix barcodes.

4.0 (07/23/2015) (11.2)


  • Added CodeBar, Code_93, EAN_8, EAN_13, ITF, UPC_A, UPC_E support to the 1D Barcode Reader module.
  • Added support for PDF417 and DataMatrix.

3.0 (08/13/2015) (DWT11.1)


  • Added support for QR Code and Industrial 2 of 5.

2.0 (07/17/2015) (DWT11.0, internal barcode dll version 9.6)


  • Added support for reading CodeBar, Code_93, EAN_8, EAN_13, ITF, UPC_A, UPC_E.


  • Fixed the bug in the Barcode Reader add-on where barcode location fails for 200 DPI.

1.0 (01/20/2015) (since DWT10.1~10.2, internal barcode dll version 9.5)

Updates in this version include 1D barcode improvements in accuracy and performance for Code 39 and Code128 recognition. Also image preprocessing is improved. For Code 128, the recognition ratio and speed have jumped up by as much as 30 percent.

15.0 (06/27/2019)


  • Fixed a bug where the video stream may appear distorted if the DIV to put the stream has a different aspect ratio.

14.3.1 (01/15/2019)


  • Added a new method IsModuleInstalled to detect whether the webcam module has already been installed on the local system.
  • The method GetImageURL and GetImagePartURL are renamed to GetFrameURL and GetFramePartURL.
  • Fixed a bug where the memory may fail to be freed after a frame is captured either by CaptureImage or GetFramePartURL. (11/20/2018)


  • [Webcam Addon] Added Webcam addon back for Windows with a new feature to embed the video stream on the page.

It is one of the best OCR engines available in the market. (08/13/2019)


  • [OCR Pro] Added a feature to read multiple zones in one OCR operation. (06/27/2019)


  • [OCR Pro] Fixed a bug where the OCR result may not be readable when the target language is Arabic. (11/20/2018)


  • [OCR Pro] Added a new feature to allow multiple OCR processes to run concurrently on the server side. (09/06/2018)


  • [OCR Pro | OCR Basic] Added the version number of the library to the name of the library so that different versions of the library can co-exist.
  • [OCR Pro | OCR Basic] Added a method IsModuleInstalled() to detect whether the library has been installed on the client machine. (07/17/2018)


  • [OCR Pro] Better mechanism to verify the OCR license.

1.0 (07/05/2016)


  • [Windows Only] Added OCR Professional (OCR Pro) module. The module uses Kofax's OCR engine.
  • Added methods Addon.OCRPro.Download, Addon.OCRPro.Recognize, Addon.OCRPro.RecognizeFile, Addon.OCRPro.RecognizeRect, Addon.OCRPro.RecognizeSelectedImages and an OCRResult class to use the OCR Professional seamlessly with Dynamic Web TWAIN on the client-side.
  • Added a feature to Dynamsoft Service for it to accept an OCR Request, do OCR and return the OCR Result. With this feature, the OCR professional SDK can be deployed on the server-side.
  • The OCR Professional module supports multi-thread processing as well as zonal processing.
  • The OCR Professional module supports many more than 30 languages. See a full list ›
  • The OCR Professional module supports extracting text from the following file types: TIFF (G4 / LZW / JPEG), JPEG, PDF, BMP, JPEG2000, JBIG, JBIG2, PNG, PDA, PGX, XPS, WMP, OPG, MAX, AWD, DCX, PCX.
  • The OCR Professional module enables you to save OCR results in the following formats: Searchable PDFs (including PDF/A 1-b). Text over image technology supports multiple image compression formats to reduce the size of PDF files. Text files - TXT, CSV, XML, RTF. String variable.