FAQ about Dynamic Web TWAIN

TWAIN is a protocol and Application Programming Interface (API) that standardizes communication between an application and image acquisition devices such as scanners and digital cameras. This standard allows a developer to make standard calls to any image acquisition device that supports TWAIN. Thus the application would not have to be rewritten to support every device. TWAIN has been in existence since 1992 and is governed by the TWAIN Working Group.

Dynamic Web TWAIN is a TWAIN-based scanning SDK specifically designed for web applications. It enables you to acquire images from any TWAIN compatible devices.

With the carefully designed interface, and the built-in wizard mode, Dynamic Web TWAIN is very easy to use. You can typically do your TWAIN job in several lines of code. At the same time, Dynamic Web TWAIN is very powerful. It is compatible with TWAIN specification V2.1. It has built-in JPEG encoder and decoder. It supports all three image transfer modes and many other features.

Dynamic Web TWAIN has many features specifically designed for the web environment, such as uploading and downloading images through FTP or HTTP protocol.

Dynamic Web TWAIN has several editions: ActiveX, HTML5 for Windows, HTML5 for Mac and HTML5 for Linux. Based on the browser(s) your end users use, you can decide which edition(s) to use.

• ActiveX: supports IE 6-9 on Windows by default, it can be configured to support IE 10, 11 as well;
• HTML5 for Windows: supports Firefox/Chrome 27+, IE 10/11 and Edge on Windows;
• HTML5 for Mac: supports Chrome/Firefox 27+, Safari 7+ on Mac OS.
• HTML5 for Linux: supports Chrome/Firefox 27+ on Ubuntu 10+, Debian 8 and Fedora 19+.

See the edition comparison chart to learn more details ›

Yes. Dynamic Web TWAIN communicates with the TWAIN driver of a device (scanner/camera/capture card/etc.) to control it to acquire and transfer images, so the driver needs to be installed on client machines.

Dynamic Web TWAIN can be used for controlling any work of scanners, digital cameras and any other devices which supports the TWAIN standard. Dynamic Web TWAIN can upload and download images through FTP or HTTP protocol. Proxy is also supported.

The main advantages of Dynamic Web TWAIN is that Dynamic Web TWAIN is a TRUE web scanning solution.

It is compatible with Internet Explorer, Chrome, Firefox and other browsers.

It is flexible and very small. Absolutely no supporting DLL is needed for distribution.

It can be used to upload and download image through HTTP and FTP.

It supports TIFF, JPEG, PDF and PNG compression.

You can get samples of Dynamic Web TWAIN from our sample gallery.

You can also find some basic samples with source code after installing the Dynamic Web TWAIN trial version.

Our Knowledge Base system and online documentation is always a good place for troubleshooting. If you can't find an answer there, please email us at support@dynamsoft.com.

• With the Virtual Developer Service, we communicate with you closely, analyze your requirements, propose tech solutions, and write the code, help you integrate the code in your project, do the test and maintenance.
• With standard customer support, you usually need a developer working on the TWAIN module who would then ask questions to our technical support team. With the Virtual Developer Service, you do not need a developer working on the TWAIN module and our developers participate in your project as a team member.

These files can be found under the \Resources\ folder in the installation directory of Dynamic Web TWAIN.

Please refer to Deploying Dynamic Web TWAIN on Web Server for more info.

Yes, Dynamic Web TWAIN can be deployed on Linux Servers.

Please refer to Deploying Dynamic Web TWAIN on Web Server for more information.

Windows XP, Vista, 7/8/10, etc.

• IE 6-9: ActiveX
• IE 10-11: HTML5/ActiveX
• Edge: HTML5
• Chrome/Firefox 26-: NPAPI Plug-in (obsolete)
• Chrome/Firefox 27+: HTML5

Mac OS X 10.6 and later

• Chrome/Firefox 26-, Safari 6-: NPAPI Plug-in (obsolete)
• Chrome/Firefox 27+, Safari 7+: HTML5

Ubuntu 10+, Debian 8 and Fedora 19+

• Chrome/Firefox 27+: HTML5

Yes. Dynamic Web TWAIN provides Plugin edition to work with old NPAPI-compatible Chrome and Firefox versions. Since Dynamic Web TWAIN 10, HTML5 Edition is introduced to enable TWAIN scanning in Chrome and Firefox V27+ on Windows.

Yes. Dynamic Web TWAIN is able to save image files to the file system and database. Please check this article for more details.

Yes. Dynamic Web TWAIN supports SSL.

For the information on how to work with SSL, please refer to How can I work with SSL.

Yes. You can use the FTPUserName property and the FTPPassword property.

No, it doesn't.

You can use Dynamic Web TWAIN with Dynamsoft Barcode Reader for barcode reading.

For OCR, we have 2 options for you:

• Server side OCR solution: Online demo ›
• Client side OCR solution: Online demo ›

With IfAllowLocalCache enabled, you are able to scan thousands of images since extra images will be on disk as long as buffer size hits 800MB.

The data will be encrypted and stored "C:\Documents and Settings\{User Name}\Application Data\Dynamsoft\cache" or "C:\WINDOWS\SysWOW64 {or system32}\Dynamsoft\DynamicWebTwain\ForChrome\cache". When the scan application is closed, the cached data will be removed from disk automatically.

DWObject.OpenSource();
DWObject.IfShowUI = false;
DWObject.IfDisableSourceAfterAcquire = true;
DWObject.PixelType = EnumDWT_PixelType.TWPT_BW; //Black - White 
image : EnumDWT_PixelType.TWPT_BW, GRAY image: 
EnumDWT_PixelType.TWPT_GRAY, RGB 
image: EnumDWT_PixelType.TWPT_RGB
DWObject.AcquireImage();

function BeginScan(){
    DWObject.OpenSource();
    DWObject.IfShowUI = false; //set without user interface
    DWObject.IfDisableSourceAfterAcquire = true;

    DWObject.AcquireImage();
}

function DWObject_OnPostTransfer(){
    DWObject.SaveAsBMP("C:\\temp.bmp",0);
}

DWObject.SelectSource();
DWObject.OpenSource();
DWObject.IfShowUI = false;
//Set Image Layout
DWObject.Unit = EnumDWT_UnitType.TWUN_INCHES;
DWObject.SetImageLayout(0, 0, 5, 5);
DWObject.AcquireImage(); 

DWObject.OpenSourceManager();

for(i = 0, i<=DWObject.SourceCount - 1,i++){
    if (DWObject.GetSourceNameItems(i) == "Specified device name")
        DWObject.SelectSourceByIndex (i);
}

//if can't find the specified source, it'll select default source
DWObject.AcquireImage(); 

DWObject.IfShowUI = false;
DWObject.IfDisableSourceAfterAcquire = true;
DWObject.OpenSource();
DWObject.IfShowIndicator = false;
DWObject.AcquireImage();

DWObject.SelectSource();
DWObject.OpenSource();

//Set XRESOLUTION current value.
DWObject.Capability = 0x1118; //ICAP_XRESOLUTION
DWObject.CapType = 5; //TWON_ONEVALUE
DWObject.CapValue = 300;
if (DWObject.CapSet == false){
    alert( "Failed to set the x-resolution. " + DWObject.ErrorString);
}

//Set YRESOLUTION current value.
DWObject.Capability = 0x1119; //ICAP_YRESOLUTION
DWObject.CapType = 5; //TWON_ONEVALUE
DWObject.CapValue = 200;
if (DWObject.CapSet == false){
   alert( "Failed to set the y-resolution." + DWObject.ErrorString);
}

DWObject.AcquireImage();

DWObject = document.getElementById("dwtcontrolContainer");
//dwtcontrolContainer is the id of the Dynamic Web TWAIN on the page (An object or an embed).
function btnScan_onclick() 
{
DWObject.SelectSource();
DWObject.OpenSource();
DWObject.AcquireImage();
}
function btnUpload_onclick() 
{
var strActionPage;
var strHostIP;
var CurrentPathName = unescape(location.pathname); // get current PathName in 
plain ASCII 
var CurrentPath = CurrentPathName.substring(0, CurrentPathName.lastIndexOf("/") 
+ 1); 
strActionPage = CurrentPath + "SaveToFile.aspx"; //the ActionPage's file path
strHostIP = "localhost"; //The host's IP or name 
DWObject.HTTPPort = 80; 
DWObject.HTTPUploadThroughPost(strHostIP,0,strActionPage,"imageData.tif");
if (DWObject.ErrorCode != 0)
alert(DWObject.ErrorString);
else //succeed
alert("Image Uploaded successfully");
}

var iDocumentCounter =0;

function BeginScan(){
    DWObject.OpenSource();

    DWObject.IfShowUI = false;
    DWObject.IfDisableSourceAfterAcquire = true;
    If(DWObject.Duplex != EnumDWT_DUPLEX.TWDX_NONE)
        DWObject.IfDuplexEnabled = true; //enable duplex

DWObject.IfFeederEnabled = true;
    if (DWObject.IfFeederEnabled == true){
         DWObject.XferCount = -1;

         if(DWObject.IfFeederLoaded == True)
             DWObject.AcquireImage();
    }
}

function DWObject_OnPosttransfer(){
iDocumentCounter = iDocumentCounter + 1;

if(DWObject.SaveAsBMP("C:\\Image\\" + iDocumentCounter + ".bmp", 0) == false)
    alert( DWObject.ErrorString);
}

You can use the IfSSL property. The following JavaScript Sample shows how to use the IfSSL property.

function btnUpload_onclick() 
{
   DWObject.HTTPPort = 80; 
   DWObject.IfSSL = false; // if 80 is the port number of 
non-secure port

   /* 
   DWObject.HTTPPort = 443; 
   DWObject.IfSSL = true; // if 443 is the port number of secure 
port
   */

   DWObject.HTTPUploadThroughPost("127.0.0.1", 0, 
"/SaveToFile.php", "imageData.jpg");

   if (DWObject.ErrorCode != 0)
      alert(DWObject.ErrorString);
   else //succeed
     alert("Successful");
}

function Scan_Click(){
   DWObject.AcquireImage();
}
function DWObject_OnPostTransfer(){
   DWObject.CloseSource();
   DWObject.IfTiffMultiPage = true;
   DWObject.SaveAsTIFF("SaveAsTIFF.tif", 0);
   if (DWObject.ErrorCode != 0)
      alert (DWObject.ErrorString);
   else //succeed
      alert ("Successful");
}

You can use the RotateLeft method and the RotateRight method.

You can view a specified image or go through all the images in buffer by updating the value of the API CurrentImageIndexInBuffer.

function NextImage_Click(){
   if (DWObject.HowManyImagesInBuffer == 0) 
   
      alert ("There is no image in buffer");

   DWObject.CurrentImageIndexInBuffer += 1;
}

function DuplexScan_Click(){
   DWObject.SelectSource();
   DWObject.OpenSource();
   DWObject.IfShowUI = false;
   DWObject.IfDuplexEnabled = true; //enable duplex
   DWObject.AcquireImage();
} 

You can use the PixelFlavor property.