10 Rules for Evaluating Web TWAIN Components

Apr 1


Adrian Cobb

Adrian Cobb

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This article offers 10 rules for software developers to evaluate web scanning SDK. Understanding and following these 10 rules will make the development work much easier and faster.


TWAIN is a standardized software protocol that gives a universal standard that communicates between applications and image acquisition devices,10 Rules for Evaluating Web TWAIN Components Articles like scanners and digital cameras. As web applications become increasingly popular, many TWAIN applications also have to work with web applications.

This white paper is for software developers building web applications that acquire images from TWAIN-compatible devices through web browsers. The paper offers some rules to live by when looking for a TWAIN component. By simply following these rules you will find a solution that will save you time and enhance your productivity.

What to Look for when looking for Web Scanning Components

Easy to Develop

Rule #1: A web scanning component should make web development easier.

The TWAIN 2.1 specification is really a pain-staking 664 pages long. It can take weeks just to read through the document let alone get a full understanding of the specification. Additionally, once you've grasped TWAIN, the amount of work to enable image compression codec, like TIFF, JPEG or PNG, and image upload/download features can be overwhelming. As a result, creating a web scanning solution from the scratch is almost impossible.

Web Page Load Time

Rule #2: A web scanning component must be small for lightning-fast rendering.

When an end user visits a web page with the ActiveX/Plug-in component for the first time, the control must be downloaded from the web server to the user's browser and then installed. The greater the control size, the longer it takes to download. Users' patience for slow downloads is thin, so every second counts.

Image Upload Time

Rule #3: A web scanning component must support multiple compression formats.

When a scanned image is large the upload time increases and the possibility of upload failure is higher. Here's a good example: the image size of a color A4 document scanned in 200DPI is 10.41 megabytes. For an ADSL connection, this will take more than 10 minutes to upload. A three-page document will take three times the time to load.

You can counter this problem by utilizing image compression technologies, like JPEG and PNG. They significantly decrease the size of the image and, in turn, the time for uploading. Additionally they prevent upload failure.
Different compression methods have distinct features. For instance, JPEG has a high compression rate but is lossy, which makes JPEG format unsuitable for document images that require high precision. Alternatively, PNG format is lossless, which means it retains all the details throughout the compression process.

User Interaction

Rule #4: A web scanning component must allow you to build rich gui applications.

User interaction--or graphical user interface (UI)--is an important part of every application. In many cases, good UI is paramount to a web application's success. Your web scanning application might use the scanner's built-in UI or your own custom-developed interface to manipulate the scanner, depending on the scenario.

Additionally, users may need to preview scanned images or edit them before uploading them to a web server. A scanning control that enables a rich user experience can differentiate your applications from competitors' products.

Multi-page Document Support

Rule #5: A TWAIN component must support multi-page format, such as TIFF and PDF.

Many documents have multiple pages. If each page is stored as being a separate scanned image, retrieving and viewing the document involves handling multiple images. Being able to store all pages of a document in a single file makes it much better to manage multiple-page documents.


Rule #6: The TWAIN component must be marked as "safe for scripting" and should be digitally signed.

Security is an ever-growing concern for end users. If a user downloads and installs a control on their computer, it's possible that the control can do almost anything to the pc. Therefore, you must be able to build end users' confidence about security issues.

When a publisher marks a control as 'safe for scripting', the publisher promises that the control will not intentionally harm the end users??å computer. If the control intentionally damages the system, the publisher assumes legal responsibility.

If the component is digitally signed, a dialog box with the publisher's legal name will appear when a customer uses the scanning component for the first time. The user can choose whether they want to install the component during the download and install process. If the control is altered after the publisher has signed it, the digital signature will be broken and also the user will be informed. This makes it impossible for the signed control to be infected by a virus or maliciously changed by hackers.

At the same time, if a control isn't marked as safe for scripting or is not digitally signed, the default setting of popular browsers--like Internet Explorer and Firefox?awill simply prevent the control from downloading or initializing.

Web Browser and Os Compatibility

Rule #7: The scanning control must support all major web browsers.

In most cases, you won't know which browser and operating system your end users will use?aMicrosoft Internet Explorer 32-bit/64-bit, Firefox, Chrome or others on Windows/Mac. If you only support 1 or 2 browsers, you significantly limit your capability to reach a broad range of customers. Even if you know which web browser your customers are using now, it is highly likely you will need to expand your web scanning application to other browsers/operating systems sooner or later.

Web Server and Industry Standard Support

Rule #8: The scanning control must use standard technology protocols and support all major web servers.

HTTP and FTP are standard Internet protocols. A component that uses any nonstandard protocol seriously increases deployment costs for your web application. It's possible your existing infrastructure or team expertise may need you to use a specific web server. An element that uses an upload and download protocol that is not compatible with your chosen web server may cause serious headaches for your team.

Rule #9: It will help if the component vendor is a contributor to the TWAIN specification.

Being an associate member of the TWAIN Working Group, the vendor has closer relationship with the TWAIN protocol maintainers and easier access to the latest trend and development. And, the vendor can make contributions to the TWAIN specification by proposing and opt for changes.

Technical Support

Rule #10: The web scanning component vendor must provide great technical support.

TWAIN can require special experience and expertise. Without prompt and accurate support from your vendor, you won't be able to get the most out of your TWAIN component. Poor technical support can lead to hours spent fighting technical issues, or perhaps unsatisfied customers.

Our Solution - Dynamic Web TWAIN

Dynamic Web TWAIN is a TWAIN control that enables you to acquire images from any TWAIN-compatible device. It includes a variety of features created specifically for the web environment. It has been developed with four core objectives in mind:

1. User Experience - To offer applied function and powerful interaction for users
2. Security - To offer a safe component over the web
3. Compatibility - To support different browsers, web servers and protocols
4. Development - To save the time as well as for developers

Dynamic Web TWAIN can also be backed by unrivalled industry technical support.

User Experience - Powerful Interaction for Users

* Reduced web page load time
The Dynamic Web TWAIN distribution file is only 213 KB for 32-bit IE and 301 KB for 64 bit IE, while the XPI file for Firefox, Chrome and other browsers is 201 KB. The .pkg file for Mac users is 416 KB. It takes seconds to download and install to the users' web browser.

* Reduced image upload time
Dynamic Web TWAIN supports major compression methods, including JPEG, TIFF and PNG. In addition, it supports multi-page TIFF and PDF formats.

* User interaction
Dynamic Web TWAIN lets you use a scanner's built-in gui or build your own UI to control the scanner. Additionally, Dynamic Web TWAIN includes a built-in image editor to allow your end users to edit the image within their browser.

Security - Safe Component on the Web

* Marked as safe for scripting
Dynamic Web TWAIN is marked as 'safe for scripting'. Dynamsoft assumes the legal responsibilities if Dynamic Web TWAIN does any intentional damage to your users' computer.

* Digitally Signed
Dynamic Web TWAIN is signed by VeriSign.
Compatibility ?§C Support Different Browsers, Operating-system, Servers and Protocols

* Browsers and Operating Systems
Dynamic Web TWAIN has ActiveX, Plug-In and Mac editions. It supports Microsoft Internet Explorer 32 bit and 64 bit, Firefox, Chrome, Opera, and Safari on Windows/Mac platform.

* Servers
Dynamic Web TWAIN works with all major web servers, including Microsoft IIS (Internet information server), IBM Notes, Websphere, Apache, Tomcat on Windows, Linux and other platforms.

* Protocols
Dynamic Web TWAIN is compatible with File Transfer Protocol (FTP) and Hyper Text Transfer Protocol (HTTP). It also supports Secure Sockets Layer (SSL) encryption.

Development - Provide your Team a Competitive Advantage

* Reduced development time
Dynamic Web TWAIN is compatible with TWAIN specification V2.1 and with built-in TIFF, JPEG and PNG encoder and decoder, Upload/download and ActiveX/Plug-in technology. Your team can leave out the scanning component and only needs to concentrate on business requirement.

Technical support
* Unrivalled support
Dynamsoft provides unrivalled technical support in the TWAIN component industry. The tech support options include: email support; phone support; LiveHelp support, which is available 16 hours per day Monday to Friday; and scheduled desktop sharing support for complex issues.

* Virtual Developer Service
Dynamsoft provides a Virtual Developer Service. With this service, our developers participate in the implementation of your web scanning module as an active team member from requirements analysis, design, coding, testing and deployment to maintenance.

About Dynamsoft Corporation

Dynamsoft is an Associate Member of the TWAIN working group.

Dynamsoft is a software publisher developing SDKs, version control and TWAIN SDK for professional development teams. Our products are well thought-out, carefully implemented, heavily tested and well documented. Dynamsoft is striving to make the life of software developers more enjoyable. We pay special attention to details to ensure that you can focus on what's important - your business.

For more information about Dynamsoft Corporation, please visit: http://www.dynamsoft.com

For more information about Dynamic Web TWAIN, please visit:

For the demo of how Dynamic Web TWAIN can help you build a rich interactive application, please visit: