WebTwain Scan

The following APIs are compatible with TWAIN | ICA | SANE (Windows, macOS and Linux)

Methods

Properties

Events

The following APIs are compatible with TWAIN (mostly Windows, but could also be macOS)

Methods

Properties

Events

[Deprecation] The following APIs are deprecated. [Alternative] Use getCapabilities() and setCapabilities() instead.

Methods

Properties


AcquireImage

Syntax

/**
 * Start image acquisition.
 * @param deviceConfiguration Configuration for the acquisition.
 * @param successCallback A callback function that is executed if the request succeeds.
 * @param failureCallback A callback function that is executed if the request fails.
 * @argument errorCode The error code.
 * @argument errorString The error string.
 */
AcquireImage(
    deviceConfiguration?: DeviceConfiguration
): void;

AcquireImage(
    successCallBack?: () => void,
    failureCallBack?: (
        errorCode: number,
        errorString: string) => void
): void;

AcquireImage(
    deviceConfiguration?: DeviceConfiguration,
    successCallBack?: () => void,
    failureCallBack?: (
        errorCode: number,
        errorString: string) => void
): void;

interface DeviceConfiguration {
    /**
     * Whether to show the built-in User Interface from the device vendor
     */
    IfShowUI?: boolean;
    /**
     * How a pixel is represented. Basically it means whether to scan in color, grey or black & white
     */
    PixelType?: Dynamsoft.EnumDWT_PixelType;
    /**
     * How detailed is the acquisition. Measured by dots per pixel (DPI)
     */
    Resolution?: number;
    /**
     * Whether to use the document feeder or the flatbed of the device.
     */
    IfFeederEnabled?: boolean;
    /**
     * Whether to scan one side or both sides of each paper.
     */
    IfDuplexEnabled?: boolean;
    /**
     * Whether to close the built-in User Interface after aquisition. Only valid when {IfShowUI} is true.
     */
    IfDisableSourceAfterAcquire?: boolean;
    /**
     * Whether to retrieve information about the image after it's transferred.
     */
    IfGetImageInfo?: boolean;
    /**
     * Whether to retrieve extended information about the image after it's transferred.
     */
    IfGetExtImageInfo?: boolean;
    /**
     * How much extended information is retrieved. Only valid when {IfGetExtImageInfo} is true.
     */
    extendedImageInfoQueryLevel?: number
}

Usage notes

extendedImageInfoQueryLevel is 0 by default which means the following information will be retrieved (if available):

Label Value
TWEI_BARCODEX 0x1200
TWEI_BARCODEY 0x1201
TWEI_BARCODETEXT 0x1202
TWEI_BARCODETYPE 0x1203
TWEI_ENDORSEDTEXT 0x1213
TWEI_BARCODECONFIDENCE 0x121A
TWEI_BARCODEROTATION 0x121B
TWEI_BARCODETEXTLENGTH 0x121C
TWEI_BOOKNAME 0x1238
TWEI_CHAPTERNUMBER 0x1239
TWEI_DOCUMENTNUMBER 0x123A
TWEI_PAGENUMBER 0x123B
TWEI_CAMERA 0x123C
TWEI_FRAMENUMBER 0x123D
TWEI_FRAME 0x123E
TWEI_PIXELFLAVOR 0x123F
TWEI_MAGDATA 0x1243
TWEI_MAGTYPE 0x1244
TWEI_PAGESIDE 0x1245

If it's set to 1, the following will also be retrieved (if available):

Label Value
TWEI_DESHADETOP 0x1204
TWEI_DESHADELEFT 0x1205
TWEI_DESHADEHEIGHT 0x1206
TWEI_DESHADEWIDTH 0x1207
TWEI_DESHADESIZE 0x1208
TWEI_SPECKLESREMOVED 0x1209
TWEI_HORZLINEXCOORD 0x120A
TWEI_HORZLINEYCOORD 0x120B
TWEI_HORZLINELENGTH 0x120C
TWEI_HORZLINETHICKNESS 0x120D
TWEI_VERTLINEXCOORD 0x120E
TWEI_VERTLINEYCOORD 0x120F
TWEI_VERTLINELENGTH 0x1210
TWEI_VERTLINETHICKNESS 0x1211
TWEI_PATCHCODE 0x1212
TWEI_FORMCONFIDENCE 0x1214
TWEI_FORMTEMPLATEMATCH 0x1215
TWEI_FORMTEMPLATEPAGEMATCH 0x1216
TWEI_FORMHORZDOCOFFSET 0x1217
TWEI_FORMVERTDOCOFFSET 0x1218
TWEI_BARCODECOUNT 0x1219
TWEI_DESHADECOUNT 0x121D
TWEI_DESHADEBLACKCOUNTOLD 0x121E
TWEI_DESHADEBLACKCOUNTNEW 0x121F
TWEI_DESHADEBLACKRLMIN 0x1220
TWEI_DESHADEBLACKRLMAX 0x1221
TWEI_DESHADEWHITECOUNTOLD 0x1222
TWEI_DESHADEWHITECOUNTNEW 0x1223
TWEI_DESHADEWHITERLMIN 0x1224
TWEI_DESHADEWHITERLAVE 0x1225
TWEI_DESHADEWHITERLMAX 0x1226
TWEI_BLACKSPECKLESREMOVED 0x1227
TWEI_WHITESPECKLESREMOVED 0x1228
TWEI_HORZLINECOUNT 0x1229
TWEI_VERTLINECOUNT 0x122A
TWEI_DESKEWSTATUS 0x122B
TWEI_SKEWORIGINALANGLE 0x122C
TWEI_SKEWFINALANGLE 0x122D
TWEI_SKEWCONFIDENCE 0x122E
TWEI_SKEWWINDOWX1 0x122F
TWEI_SKEWWINDOWY1 0x1230
TWEI_SKEWWINDOWX2 0x1231
TWEI_SKEWWINDOWY2 0x1232
TWEI_SKEWWINDOWX3 0x1233
TWEI_SKEWWINDOWY3 0x1234
TWEI_SKEWWINDOWX4 0x1235
TWEI_SKEWWINDOWY4 0x1236
TWEI_ICCPROFILE 0x1240
TWEI_LASTSEGMENT 0x1241
TWEI_SEGMENTNUMBER 0x1242
TWEI_FILESYSTEMSOURCE 0x1246
TWEI_IMAGEMERGED 0x1247
TWEI_MAGDATALENGTH 0x1248
TWEI_PAPERCOUNT 0x1249
TWEI_PRINTERTEXT 0x124A

If it's set to 2, then besides what's mentioned in the two tables above, the Dynamci Web TWAIN library will also try to query the scanner for its own custom extended image info.

Example

The example code shows 4 ways to use the API AcquireImage()

var deviceConfiguration = {
    IfShowUI: false,
    PixelType: Dynamsoft.EnumDWT_PixelType.TWPT_RGB,
    Resolution: 300,
    IfFeederEnabled: true,
    IfDuplexEnabled: false,
    IfDisableSourceAfterAcquire: true,
    IfGetImageInfo: true,
    IfGetExtImageInfo: true,
    extendedImageInfoQueryLevel: 0
};

function successCallback() {
    console.log('successful');
}

function failureCallback(errorCode, errorString) {
    alert(errorString);
}

function AcquireImage1() {
    DWObject.SelectSource(function() {
        DWObject.OpenSource();
        DWObject.IfShowUI = false;
        DWObject.PixelType = Dynamsoft.EnumDWT_PixelType.TWPT_RGB;
        DWObject.Resolution = 300;
        DWObject.IfFeederEnabled = true;
        DWObject.IfDuplexEnabled = false;
        DWObject.IfDisableSourceAfterAcquire = true;
        DWObject.AcquireImage();
    }, failureCallback);
}

function AcquireImage2() {
    DWObject.SelectSource(function() {
        DWObject.OpenSource();
        DWObject.AcquireImage(deviceConfiguration);
    }, failureCallback);
}

function AcquireImage3() {
    DWObject.SelectSource(function() {
        DWObject.OpenSource();
        DWObject.IfShowUI = false;
        DWObject.PixelType = Dynamsoft.EnumDWT_PixelType.TWPT_RGB;
        DWObject.Resolution = 300;
        DWObject.IfFeederEnabled = true;
        DWObject.IfDuplexEnabled = false;
        DWObject.IfDisableSourceAfterAcquire = true;
        DWObject.AcquireImage(successCallback, failureCallback);
    }, failureCallback);
}

function AcquireImage4() {
    DWObject.SelectSource(function() {
        DWObject.OpenSource();
        DWObject.AcquireImage(deviceConfiguration, successCallback, failureCallback);
    }, failureCallback);
}

CloseSource

Syntax

/**
 * Close the data source (a TWAIN/ICA/SANE device which in most cases is a scanner) to free it to be used by other applications.
 */
CloseSource(): boolean;

CloseSourceAsync

Syntax

/**
 * Close the data source (a TWAIN/ICA/SANE device which in most cases is a scanner) to free it to be used by other applications.
 */
CloseSourceAsync(): Promise<boolean>;

DisableSource

Syntax

/**
 * Disable the data source (a TWAIN/ICA/SANE device which in most cases is a scanner) to stop the acquiring process. If the data source's user interface is displayed, it will be closed.
 */
DisableSource(): boolean;

Usage notes

After DisableSource() is called, the Source is still open and you can continue to acquire images by calling AcquireImage() or EnableSource() .


EnableSource

Syntax

/**
 * Enable the data source to start the acquiring process.
 */ 
EnableSource(): boolean;

Usage notes

The method is equivalent to AcquireImage() without parameters.


EnableSourceUI

Syntax

/**
 * Display the TWAIN source's built-in user interface.
 * @param successCallback A callback function that is executed if the request succeeds.
 * @param failureCallback A callback function that is executed if the request fails.
 */
EnableSourceUI(
    successCallBack: () => void,
    failureCallBack: (
        errorCode: number,
        errorString: string) => void
): void;

Usage notes

This method enables the user to manipulate the settings for scanning but not start an actual scan. It only works if the source supports the capability CAP_ENABLEDSUIONLY . User can call GetCustomDSDataEx() to save the settings in the callback successCallBack and later call SetCustomDSDataEx() to apply the settings before starting a scan.


OpenSource

Syntax

/**
 * Load a data source to get it ready to acquire images.
 */
OpenSource(): boolean;

OpenSourceAsync

Syntax

/**
 * Load a data source to get it ready to acquire images.
 */
OpenSourceAsync(): Promise<boolean>;

GetSourceNames

Syntax

/**
 * Return all available data sources (scanners, etc.) and optionally all detailed information about them.
 * @param bIncludeDetails Whether to return more details about the data sources or just their names.
 */
GetSourceNames(bIncludeDetails: boolean): string[] | ISourceDetails[];

interface SourceDetails {
    /**
     * The driver type which can be "TWAIN" | "ICA" | "SANE"
     */
    DriverType?: string;
    /**
     * Information about the driver if it's DriverType is "ICA"
     */
    DeviceInfo?: any;
    /**
     * The name of the data source. E.g. "TWAIN2 FreeImage Software Scanner".
     */
    ProductName?: string;
    /**
     * Whether it is the default source.
     */
    IsDefaultSource?: boolean;
    /**
     * Whether it is the current source.
     */
    IsCurrentSource?: boolean;
    /**
     * The family name of the data source. E.g. "Software Scan".
     */
    ProductFamily?: string;
    /**
     * The manufacturer of the data source. E.g. "TWAIN Working Group".
     */
    Manufacturer?: string;
    /**
     *
     */
    SupportedGroups?: 1073741827,
    /**
     * The version of the protocol based on which the data source is developed.
     */
    ProtocolMajor?: number;
    ProtocolMinor?: number;
    /**
     * Detailed version of the data source.
     */
    Version?: Version;
}
interface Version {
    MajorNum?: number;
    MinorNum?: number;
    Language?: number;
    Country?: number;
    Info?: string;
}

GetSourceNamesAsync

Syntax

/**
 * Return all available data sources (scanners, etc.) and optionally all detailed information about them.
 * @param bIncludeDetails Whether to return more details about the data sources or just their names.
 */
GetSourceNamesAsync(bIncludeDetails: boolean): Promise<string[] | ISourceDetails[]>;

SelectSource

Syntax

/**
 * Bring up the Source Selection User Interface (UI) for the user to choose a data source.
 * @param successCallback A callback function that is executed if the request succeeds.
 * @param failureCallback A callback function that is executed if the request fails.
 * @argument errorCode The error code.
 * @argument errorString The error string.
 */
SelectSource(
    successCallBack?: () => void,
    failureCallBack?: (errorCode: number, errorString: string) => void
): boolean | void;

Usage notes

It's recommended to use this API asynchronously by pass arguments to the parameters successCallback and failureCallback . On Windows and Windows only, you can call this method with no arguments so that it runs synchronously and return a boolean value.

Example

DWObject.SelectSource(function() {
    DWObject.OpenSource();
    DWObject.AcquireImage();
}, function(errorCode, errorString) {
    console.log(errorString);
});

SelectSourceAsync

Syntax

/**
 * Bring up the Source Selection User Interface (UI) for the user to choose a data source.
 * @param successCallback A callback function that is executed if the request succeeds.
 * @param failureCallback A callback function that is executed if the request fails.
 * @argument errorCode The error code.
 * @argument errorString The error string.
 */
SelectSourceAsync(
    successCallBack?: () => void,
    failureCallBack?: (errorCode: number, errorString: string) => void
): Promise<boolean>;

SelectSourceByIndex

Syntax

/**
 * Select a data source by its index.
 * @param index The index of the data source.
 */
SelectSourceByIndex(index: number): boolean;

Example

DWObject.SelectSourceByIndex(0);
DWObject.OpenSource();
DWObject.AcquireImage();

SelectSourceByIndexAsync

Syntax

/**
 * Select a data source by its index.
 * @param index The index of the data source.
 */
SelectSourceByIndexAsync(index: number): Promise<boolean>;

Example

DWObject.SelectSourceByIndexAsync(0)
    .then(() =>
        return DWObject.OpenSourceAsync())
    .then(() => retyrb DWObject.AcquireImage());

SetOpenSourceTimeout

Syntax

/**
 * Sets a timer which stops the data source opening process once it expires.
 * @param duration Define the duration of the timer (in milliseconds).
 */
SetOpenSourceTimeout(duration: number): boolean;

Example

DWObject.SelectSource(function() {
    DWObject.SetOpenSourceTimeout(3000);
    DWObject.OpenSource();
    DWObject.AcquireImage();
});

startScan

Syntax

/**
 * Start the acquisition by passing all settings at once.
 * @param scanSetup Configuration for the acquisition.
 */
startScan(scanSetup: ScanSetup): Promise<IScanSetup>;

interface ScanSetup {
  /**
   * An id that specifies this specific setup.
   */
  setupId?: string,
  /**
   * Whether to ignore or fail the acquistion when an exception is raised. Set "ignore" or "fail".
   */
  exception?: string,
  /**
   * The name of the data source (the scanner). If not set, the default data source is used.
   */
  scanner?: string,
  ui?: {
    /**
     * Whether to show the UI of the device.
     */
    bShowUI?: boolean,
    /**
     * Whether to show the indicator of the device.
     */
    bShowIndicator?: boolean,
  },
  /**
   * The TWAIN transfer mode.
   */
  transferMode?: Dynamsoft.EnumDWT_TransferMode | number,
  /**
   * Set how the transfer is done.
   */
  fileXfer?: {
    /**
     * Specify the file name (or pattern) for file transfer.
     * Example: "C:\\WebTWAIN<%06d>.bmp"
     */
    fileName?: string,
    /**
     * Specify the file format.
     */
    fileFormat?: Dynamsoft.EnumDWT_FileFormat | number,
    /**
     * Specify the quality of JPEG files.
     */
    jpegQuality?: number,
    /**
     * Specify the compression type of the file.
     */
    compressionType?: Dynamsoft.EnumDWT_CompressionType | number
  }
  /**
   * Set where the scanned images are inserted.
   */
  insertingIndex?: number,
  /**
   * The profile is a base64 string, if present, it overrides settings and more settings.
   */
  profile?: string,
  /**
   * Basic settings.
   */
  settings?: {
    /**
     * "ignore" (default) or "fail".
     */
    exception?: string,
    /**
     * Specify the pixel type.
     */
    pixelType?: Dynamsoft.EnumDWT_PixelType | number,
    /**
     * Specify the resolution.
     */
    resolution?: number,
    /**
     * Whether to enable document feader.
     */
    bFeeder?: boolean,
    /**
     * Whether to enable duplex scan.
     */
    bDuplex?: boolean
  },
  moreSettings?: {
    /**
     * "ignore" (default) or "fail".
     */
    exception?: string,
    /**
     * Specify the bit depth.
     */
    bitDepth?: number,
    /**
     * Specify the page size.
     */
    pageSize?: Dynamsoft.EnumDWT_CapSupportedSizes | number,
    /**
     * Specify the unit.
     */
    unit?: Dynamsoft.EnumDWT_UnitType | number,
    /**
     * Specify a layout to scan, if present, it'll override pageSize.
     */
    layout?: {
      left?: number,
      top?: number,
      right?: number,
      bottom?: number
    },
    /**
     * Specify the pixel flavor.
     */
    pixelFlavor?: Dynamsoft.EnumDWT_CapPixelFlavor | number,
    /**
     * Specify Brightness.
     */
    brightness?: number,
    /**
     * Specify contrast.
     */
    contrast?: number,
    /**
     * Specify how many images are transferred per session.
     */
    nXferCount?: number,
    /**
     * Whether to enable automatic blank image detection and removal.
     */
    autoDiscardBlankPages?: boolean,
    /**
     * Whether to enable automatic border detection.
     */
    autoBorderDetection?: boolean,
    /**
     * Whether to enable automatic skew correction.
     */
    autoDeskew?: boolean,
    /**
     * Whether to enable automatic brightness adjustment.
     */
    autoBright?: boolean
  },
  /**
   * A callback triggered before the scan, after the scan and after each page has been transferred.
   */
  funcScanStatus?: (status: Status) => void,
  /**
   * Set up how the scanned images are outputted.
   */
  outputSetup?: {
    /**
     * Output type. "http" is the only supported type for now.
     */
    type?: string,
    /**
     * Set the output format.
     */
    format?: Dynamsoft.EnumDWT_ImageType | number,
    /**
     * Specify how many times the library will try the output.
     */
    reTries?: 3,
    /**
     * Whether to use the FileUploader.
     */
    useUploader?: false,
    /**
     * Whether to upload all images in one HTTP post.
     */
    singlePost?: boolean,
    /**
     * Whether to show a progress bar when outputting.
     */
    showProgressBar?: boolean,
    /**
     * Whether to remove the images after outputting.
     */
    removeAfterOutput?: boolean,
    /**
     * A callback triggered during the outputting.
     * @argument fileInfo A JSON object that contains the fileName, percentage, statusCode, responseString, etc.
     */
    funcHttpUploadStatus?: (fileInfo: any) => void,
    /**
     * Setup for PDF output.
     */
    pdfSetup?: {
      author?: string,
      compression?: Dynamsoft.EnumDWT_PDFCompressionType | number,
      creator?: string,
      /**
       * Example: 'D:20181231'
       */
      creationDate?: string,
      keyWords?: string,
      /**
       * Example: 'D:20181231'
       */
      modifiedDate?: string,
      producer?: string,
      subject?: string,
      title?: string,
      version?: number,
      quality?: number
    },
    /**
     * Setup for TIFF output.
     */
    tiffSetup?: {
      quality?: number,
      compression?: Dynamsoft.EnumDWT_TIFFCompressionType | number,
      /**
       * Specify Tiff custom tags.
       */
      tiffTags?: TiffTag[]
    },
    /**
     * Setup for HTTP upload via Post.
     */
    httpParams?: {
      /**
       * Target of the request.
       * Example: "http://dynamsoft.com/receivepost.aspx"
       */
      url?: string,
      /**
       * Custom headers in the form.
       * Example: {md5: ""}
       */
      headers?: any,
      /**
       * Custom form fields.
       * Example: {"UploadedBy": "Dynamsoft"}
       */
      formFields?: any,
      /**
       * The maximum size of a file to be uploaded (in bytes).
       */
      maxSizeLimit?: number,
      /**
       * Specify how many threads (<=4) are to be used. Only valid when {useUploader} is true.
       */
      threads?: number,
      /**
       * Specify the names for the files in the form.
       * Example: "RemoteName<%06d>"
       */
      remoteName?: string,
      /**
       * Specify the name(s) (pattern) of the uploaded files.
       * Example: "uploadedFile<%06d>.jpg"
       */
      fileName?: string
    }
  }
}

CancelAllPendingTransfers

Syntax

/**
 * Cancels all pending transfers.
 */ 
CancelAllPendingTransfers(): boolean;

Usage notes

This method is only valid in the events OnPreAllTransfers, OnPreTransfer and OnPostTransfer.


CloseSourceManager

Syntax

/**
 * Closes and unloads Data Source Manager.
 */
CloseSourceManager(): boolean;

CloseSourceManagerAsync

Syntax

/**
 * Closes and unloads Data Source Manager.
 */
CloseSourceManagerAsync(): Promise<boolean>;

CloseWorkingProcess

Syntax

/**
 * Closes the scanning process to release resources on the machine.
 */
CloseWorkingProcess(): boolean;

Usage notes

In the HTML5 edition, Dynamic Web TWAIN uses a separate process to communicate with the scanners. When it's not scanning, you can choose to close this process to release the resources (CPU, memory, etc.) used on the machine.


FeedPage

Syntax

/**
 * Ejects the current page and begins scanning the next page in the document feeder.
 */
FeedPage(): boolean;

Usage notes

Use this method after OpenSource() is called and make sure IfFeederEnabled is true .


GetCustomDSData

Syntax

/**
 * Get the custom data source data and saves the data in a specified file.
 * @param fileName The path of the file to save the data source data to.
 */
GetCustomDSData(fileName: string): boolean;

Example

DWObject.GetCustomDSData("C:\\customDSData");

GetCustomDSDataEx

Syntax

/**
 * Gets custom DS data and returns it in a base64 string.
 */
GetCustomDSDataEx(): string;

GetDeviceType

Syntax

/**
 * Inspect the current data source and return whether it is a scanner, a webcam, etc.
 */
GetDeviceType(): number;

Usage notes

Value Description
0 Failed
1 Digital Camera
2 Flatbed-only scanner
3 Flatbed, feeder, auto feed
4 Feeder-only scanner, auto feed
5 Flatbed, feeder, without auto feed
6 Feeder-only scanner, without auto feed
7 Webcam

GetSourceNameItems

Syntax

/**
 * Get the name of a data source by its index in data source manager source list.
 * @param index The index of the data source.
 */
GetSourceNameItems(index: number): string;

OpenSourceManager

Syntax

/**
 * Load and open data source manager.
 */
OpenSourceManager(): boolean;

Usage notes

If application identification needs to be set, it should be set before this API.


OpenSourceManagerAsync

Syntax

/**
 * Load and open data source manager.
 */
OpenSourceManagerAsync(): Promise<boolean>;

Usage notes

If application identification needs to be set, it should be set before this API.


ResetImageLayout

Syntax

/**
 * Reset the image layout in the data source.
 */
ResetImageLayout(): boolean;

Usage notes

To set the image layout manually, you can use SetImageLayout()


RewindPage

Syntax

/**
 * If called while {IfFeederEnabled} property is true, the data source will return the current page to the input area and return the last page from the output area into the acquisition area.
 */
RewindPage(): boolean;

Usage notes

Use this method after OpenSource() method and make sure IfFeederEnabled is true .


SetCustomDSData

Syntax

/**
 * Sets custom data source data to be used for scanning, the data is stored in a file which can be regarded as a scanning profile.
 * @param fileName The path  of the file.
 */
SetCustomDSData(fileName: string): boolean;

Usage notes

Typically, the data source data file is created by the method GetCustomDSData().


SetCustomDSDataEx

Syntax

/**
 * Set custom data source data to be used for scanning, the input is a base64 string.
 * @param dsDataString The string that contains custom data source data.
 */
SetCustomDSDataEx(dsDataString: string): boolean;

Usage notes

Typically the data source data string is created by the method GetCustomDSDataEx()


SetFileXferInfo

Syntax

/**
 * Set the file transfer information to be used in File Transfer mode.
 * @param fileName The path to transfer the file to.
 * @param fileFormat The format of the file.
 */
SetFileXferInfo(
    fileName: string,
    fileFormat: Dynamsoft.EnumDWT_FileFormat | number
): boolean;

Usage notes

Make sure the format you set is supported by the data source.

Example argument for the parameter fileName

  • "C:\webtwain.jpg": The next scanned image will be compressed as a JPEG file named webtwain and transferred to "C:\".
  • "C:\webtwain" + <> + ".jpg": The scanned images will result in "C:\webtwain1.jpg", "C:\webtwain2.jpg", "C:\webtwain3.jpg", etc.
  • "C:\webtwain" + <%06d> + ".jpg": The scanned images will result in "C:\webtwain000001.jpg", "C:\webtwain000002.jpg", "C:\webtwain000003.jpg", etc.

Check out the available formats Dynamsoft. EnumDWT_FileFormat.

Example

DWObject.OpenSource();
DWObject.TransferMode = Dynamsoft.EnumDWT_TransferMode.TWSX_FILE;
if (DWObject.TransferMode === Dynamsoft.EnumDWT_TransferMode.TWSX_FILE) {
    if (DWObject.SetFileXferInfo(
            "C:\\Temp\\WebTWAIN&lt;&gt;.bmp",
            EnumDWT_FileFormat.TWFF_BMP
        )) {
        DWObject.IfShowUI = true;
        DWObject.AcquireImage();
    }
}

SetImageLayout

Syntax

/**
 * Set the left, top, right, and bottom sides of the image layout rectangle for the current data source. The image layout rectangle defines a frame of the data source's scanning area to be acquired.
 * @param left Specify the rectangle (leftmost coordinate).
 * @param top Specify the rectangle (topmost coordinate).
 * @param right Specify the rectangle (rightmost coordinate).
 * @param bottom Specify the rectangle (bottommost coordinate).
 */
SetImageLayout(
    left: number,
    top: number,
    right: number,
    bottom: number
): boolean;

Usage notes

The arguments set to the parameters left , top , right , bottom are based on the value of the Unit property which is inches by default.

This API is device-dependent. If a data source doesn't support the customization of the scan area, this method might not work correctly.

Since there are several ways to negotiate the scan area, it becomes confusing when deciding what should take precedence.

The TWAIN Working Group has suggested the following behavior

Example

DWObject.SelectSource();
DWObject.OpenSource();
DWObject.IfShowUI = false;
DWObject.Unit = Dynamsoft.EnumDWT_UnitType.TWUN_PIXELS;
DWObject.SetImageLayout(50, 50, 100, 100);
DWObject.AcquireImage();

BitDepth

Syntax

/**
 * Return or set the pixel bit depth for the current value of `PixelType` .
 */
BitDepth: number;

Usage notes

Set this property after OpenSource() and before AcquireImage() .

By default, the bit depth is 1 for TWPT_BW , 8 for TWPT_GRAY and 24 for TWPT_RGB .


IfAppendImage

Syntax

/**
 * Return or set whether newly acquired images are inserted or appended.
 */
IfAppendImage: boolean;

Usage notes

The value of this property defaults to true , which means that the newly acquired image will be appended to the last image in the buffer.

If it's set to false , the images will be inserted before the current image. The important thing to note is that, by design, the current image is always the last acquired one which means that the images acquired after setting IfAppendImage to false will be displayed / retained in the reverse order.


IfDisableSourceAfterAcquire

Syntax

/**
 * Return or set whether to close the user interface after all images have been acquired.
 */
IfDisableSourceAfterAcquire: boolean;

Usage notes

This property only makes sense when IfShowUI is set to true .


IfDuplexEnabled

Syntax

/**
 * Return or set whether to enable duplex scanning (in other words, whether to scan both sides of the paper).
 */
IfDuplexEnabled: boolean;

Usage notes

Set this property after OpenSource() and before AcquireImage() .

Not all scanners support duplex scanning. To confirm, check the user manual of the device or check the value of Duplex after OpenSource() .


IfFeederEnabled

Syntax

/**
 * Return or set whether a data source's Automatic Document Feeder (ADF) is enabled for scanning.
 */
IfFeederEnabled: boolean;

Usage notes

Set this property after OpenSource() and before AcquireImage() .

If the property is set to true , the data source will try acquiring images from the document feeder first. If the data source doesn't have a document feeder, the flatbed will be used.


IfShowUI

Syntax

/**
 * Return or set whether the data source displays the user interface when scanning.
 */
IfShowUI: boolean;

Usage notes

If the property is set to true , the data source will display its user interface when AcquireImage() is called. Otherwise, the UI will not be displayed and the scan will start immediately.


ImageCaptureDriverType

Syntax

/**
 * Return or set the driver type which determines the type of sources to use.
 */
ImageCaptureDriverType: Dynamsoft.EnumDWT_Driver | number;

Usage notes

Set this property right after the SDK is initialized or after calling CloseSourceManager() and OpenSourceManager() .

The allowed values for EnumDWT_Driver are

Label Value Description
TWAIN 0 Use data sources that conforms to the TWAIN protocol
ICA 3 Use data sources that conforms to the Image Capture Architecture
SANE 3 Use data sources that conforms to the SANE API
TWAIN_AND_ICA 4 Use both TWAIN and ICA data sources
TWAIN_AND_TWAIN64 4 Use both 32bit and 64bit TWAIN drivers
TWAIN64 5 Use 64bit TWAIN sources

PageSize

Syntax

/**
 * Return or set the page size the data source uses to acquire images.
 */
PageSize: Dynamsoft.EnumDWT_CapSupportedSizes | number;

PixelType

Syntax

/**
 * Return or set the pixel type used when acquiring images. 
 */
PixelType: Dynamsoft.EnumDWT_PixelType | number;

Resolution

Syntax

/**
 * Return or set the resolution used when acquiring images.
 */
Resolution: number;

SourceCount

Syntax

/**
 * Returns how many data sources are available on the local system.
 */
readonly SourceCount: number;

Brightness

Syntax

/**
 * Return or set the brightness to be used for scanning by the data source.
 */
Brightness: number;

Usage notes

Set this property after OpenSource() and before AcquireImage() .

Typically, the value range is -1000 ~ 1000 where -1000 indicates the darkest and 1000 the brightest.


Contrast

Syntax

/**
 * Return or set Contrast to be used for scanning by the data source.
 */
Contrast: number;

Usage notes

Set this property after OpenSource() and before AcquireImage() .

Typically, the value range is -1000 ~ 1000 where -1000 indicates the darkest and 1000 the brightest.


CurrentSourceName

Syntax

/**
 * Return the device name of current source. 
 */
readonly CurrentSourceName: string;

Usage notes

If no source is currently selected, this property returns "".


DataSourceStatus

Syntax

/**
 * Return a value that indicates the data source status.
 */
DataSourceStatus: number;

Usage notes

Value Description
0 The data source is closed.
1 The data source is opened.
2 The data source is enabled.
3 The data source is acquiring images.

DefaultSourceName

Syntax

/**
 * Return the name of the default source.
 */
DefaultSourceName: string;

Duplex

Syntax

/**
 * Return whether the source supports duplex. If yes, it further returns the level of duplex the data source supports.
 */
readonly Duplex: Dynamsoft.EnumDWT_DUPLEX | number;

Usage notes

Label Value Description
TWDX_NONE 0 duplex is not supported
TWDX_1PASSDUPLEX 1 1-pass duplex
TWDX_2PASSDUPLEX 2 2-pass duplex

1-pass means the paper gets scanned on both sides at the same time. 2-pass means the paper passes the light bar twice to get both sides scanned separately.


IfAutoBright

Syntax

/**
 * Return or set whether to enable the data source's auto-brightness feature.
 */
IfAutoBright: boolean;

IfAutoDiscardBlankpages

Syntax

/**
 * Return or set whether the data source (the scanner) discards blank images during scanning automatically.
 */
IfAutoDiscardBlankpages: boolean;

Usage notes

The property works only if the device and its driver supports discarding blank pages. You can find whether your device supports this capbility from its user manual.

Alternatively, the Dynamic Web TWAIN library can also detect blank images after they are transferred.


IfAutoFeed

Syntax

/**
 * Return or set whether to enable the data source's automatic document feeding process.
 */
IfAutoFeed: boolean;

Usage notes

If set to true , the data source will automatically feed the next page from the document feeder as soon as the previous page is scanned.


IfAutomaticBorderDetection

Syntax

/**
 * Return or set whether to enable the data source's automatic border detection feature.
 */
IfAutomaticBorderDetection: boolean;

Usage notes

The property works only if the device and its driver support detecting the border automatically. You can find whether your device supports this capbility from its user manual.

Once enabled, the data source (scanner) will automatically detect the borders of the document so that no extra margins are scanned.


IfAutomaticDeskew

Syntax

/**
 * Return or set whether to enable the data source's automatic skew correction feature.
 */
IfAutomaticDeskew: boolean;

Usage notes

The property works only if the device and its driver supports automatical deskewing. You can find whether your device supports this capbility from its user manual.


IfAutoScan

Syntax

/**
 * Return or set whether to enable the data source's automatic document scanning process.
 */
IfAutoScan: boolean;

Usage notes

This property is only valid when IfFeederEnabled is set to true .

The fundamental assumption behind this property is that the device may be able to capture the number of images indicated by the property XferCount without waiting for the Application to request the image transfers. This is only possible if the device has internal buffers capable of caching the images it captures.


IfFeederLoaded

Syntax

/**
 * Return whether or not there are documents loaded in the data source's feeder.
 */
readonly IfFeederLoaded: boolean;

Usage notes

This property is only valid when IfFeederEnabled and IfPaperDetectable are true .


IfPaperDetectable

Syntax

/**
 * Return whether the Source has a paper sensor that can detect pages on the ADF or Flatbed.
 */
readonly IfPaperDetectable: boolean;

Usage notes

Check this property after OpenSource() is called.


IfShowIndicator

Syntax

/**
 * Return or set whether the data source displays a progress indicator during acquisition and transfer.
 */
IfShowIndicator: boolean;

Usage notes

This property works only when IfShowUI is set to false .

The indicator will only be hidden if you set both IfShowUI and IfShowIndicator to false .


IfUIControllable

Syntax

/**
 * Return whether the data source supports acquisitions with the UI (User Interface) disabled.
 */
readonly IfUIControllable: boolean;

Usage notes

Check this property after OpenSource() is called.


IfUseTwainDSM

Syntax

/**
 * Return or set whether the new TWAIN DSM (data source Manager) is used for acquisitions. The new TWAIN DSM is a DLL called 'TWAINDSM.dll' while the default | old DSM is called 'twain_32.dll'.
 */
IfUseTwainDSM: boolean;

Usage notes

This property should be set before any TWAIN related methods or properties are called or set.


ImageLayoutFrameBottom

Syntax

/**
 * Return the value of the bottom edge of the current image frame (in Unit).
 */
readonly ImageLayoutFrameBottom: number;

ImageLayoutFrameLeft

Syntax

/**
 * Return the value of the left edge of the current image frame (in Unit).
 */
readonly ImageLayoutFrameLeft: number;

ImageLayoutFrameRight

Syntax

/**
 * Return the value of the right edge of the current image frame (in Unit).
 */
readonly ImageLayoutFrameRight: number;

ImageLayoutFrameTop

Syntax

/**
 * Return the value of the top edge of the current image frame (in Unit).
 */
readonly ImageLayoutFrameTop: number;

ImageLayoutDocumentNumber

Syntax

/**
 * Return the document number of the current image.
 */
readonly ImageLayoutDocumentNumber: number;

ImageLayoutPageNumber

Syntax

/**
 * Return the page number of the current image.
 */
readonly ImageLayoutPageNumber: number;

ImageBitsPerPixel

Syntax

/**
 * Return the bit depth of the current image.
 */
readonly ImageBitsPerPixel: number;

ImageLength

Syntax

/**
 * Return the length of the current image.
 */
readonly ImageLength: number;

ImageWidth

Syntax

/**
 * Return the width of the current image.
 */
readonly ImageWidth: number;

ImageXResolution

Syntax

/**
 * Return the horizontal resolution of the current image.
 */
readonly ImageXResolution: number;

ImageYResolution

Syntax

/**
 * Return the vertical resolution of the current image.
 */
readonly ImageYResolution: number;

ImagePixelType

Syntax

/**
 * Return the pixel type of the current image.
 */
readonly ImagePixelType: Dynamsoft.EnumDWT_PixelType | number;

MagData

Syntax

/**
 * Return the data of the magnetic data if the data source supports magnetic data recognition.
 */
readonly MagData: string;

MagType

Syntax

/**
 * Return the type of the magnetic data if the data source supports magnetic data recognition.
 */
readonly MagType: Dynamsoft.EnumDWT_MagType | number;

Usage notes

The numbers returned by these APIs are based on the value of the Unit property which by default means "inches".

These APIs are only valid in the callbacks for the events OnPreTransfer and OnPostTransfer.

MagData and MagType are device-dependent. Check the user manual of the device to see if magnetic data recognition is supported.


PendingXfers

Syntax

/**
 * Return the number of transfers the data source is ready to supply upon demand.
 */
readonly PendingXfers: number;

Usage notes

This property is only valid in the event OnPostTransfer.

The data source returns -1 if it is not sure how many transfers are pending which normally occurs when the ADF (Automatic Document Feeder) is used.


PixelFlavor

Syntax

/**
 * Return or set the pixel flavor to be used for acquiring images.
 */
PixelFlavor: number;

Usage notes

Available values:

  • 0: Chocolate. Zero pixel represents darkest shade
  • 1: Vanilla. Zero pixel represents lightest shade.

TransferMode

Syntax

/**
 * Return or set the data source's transfer mode.
 */
TransferMode: Dynamsoft.EnumDWT_TransferMode | number;

Usage notes

Allowed values are

  • TWSX_NATIVE | 0: The default mode. In this mode, the whole image is transfered in a single memory block.
  • TWSX_FILE | 1: In this mode, the image is transfered to a specified file on the disk directly. This mode is ideal when transferring large images that might encounter memory limitations with Native mode. Check out SetFileXferInfo for more information.
  • TWSX_MEMORY | 2: In this mode, the image is transferred in multiple memory blocks. It's ideal for transferring very large images or a large number of images in a short time.

TWSX_NATIVE and TWSX_MEMORY are required by all TWAIN data sources while TWSX_FILE is not. Therefore, make sure the data source supports TWSX_FILE before you use it.


Unit

Syntax

/**
 * Return or set the unit of measure for all quantities.     
 */
Unit: Dynamsoft.EnumDWT_UnitType | number;

Usage notes

Allowed values are

Label Value Description
TWUN_INCHES 0 inches(Default)
TWUN_CENTIMETERS 1 centimeters
TWUN_PICAS 2 picas
TWUN_POINTS 3 points
TWUN_TWIPS 4 twips
TWUN_PIXELS 5 pixels
TWUN_MILLIMETERS 6 millimeters

XferCount

Syntax

/**
 * Return and set the number of images your application is willing to accept for each scan job.
 */ 
XferCount: number;

Usage notes

Allowed values are between -1 and 215 where -1 indicate multiple images.


OnPostAllTransfers

Syntax

/**
 * This event is triggered when all page(s) have been scanned and transferred.
 */
RegisterEvent('OnPostAllTransfers',function(){});

Usage notes

This event fires after all pages in the document feeder have been scanned and transferred. This is a good place to upload the images, detect barcodes, discard blank pages, etc.

Example

DWObject.RegisterEvent('OnPostAllTransfers',
    function() {
        console.log("All images are transferred.");
    }
);

OnPostTransfer

Syntax

/**
 * This event is triggered after each page has been scanned and transferred.
 * @argument outputInfo Detailed information about the image that just got transferred.
 */ 
RegisterEvent('OnPostTransfer',function(outputInfo: OutputInfo) {});

Example

DWObject.RegisterEvent('OnPostTransfer',
    function() {
        console.log("An image has been scanned");
    }
);

OnPostTransferAsync

Syntax

/**
 * This event is triggered after each page has been scanned and transferred. This is the asynchronous counterpart to the synchronous event {OnPostTransfer}.
 * @argument outputInfo Detailed information about the image that just got transferred.
 */ 
RegisterEvent('OnPostTransferAsync',function(outputInfo: OutputInfo) {});

Usage notes

interface outputInfo {
    /**
     * Id of the image if it's transferred to the buffer.
     */
    imageId?: number;
    /**
     * Path of the image if it's transferred to the disk.
     */
    Path?: string;
    /**
     * Information about the image.
     */
    imageInfo?: object;
    /**
     * Extended information about the image.
     */
    extendedImageInfo?: object;
}

Example

DWObject.RegisterEvent('OnPostTransferAsync',
    function(outputInfo) {
        console.log("The image ID is " + outputInfo.imageId);
    }
);

OnPreAllTransfers

Syntax

/**
 * This event is triggered when all images are scanned and ready to be transferred.
 */
RegisterEvent('OnPreAllTransfers',function(){});

Usage notes

Multiple transfers may occur in two cases

  • Multiple images are scanned through the ADF(Auto Document Feeder)
  • Multiple frames are scanned on one single page

In such cases, the event OnPreTransfer is triggered multiple times but OnPreAllTransfers is triggerred only once.

In the callback function of this event, you can call CancelAllPendingTransfers() to cancel all the transfers.


OnPreTransfer

Syntax

/**
 * This event is triggered when a page has been scanned and is ready to be transferred.
 */
RegisterEvent('OnPreTransfer',function(){...});

Usage notes

In the callback function of this event, you can

  • Check PendingXFERs for the number of pending transfers.
  • Check the information about the transferred image including ImageLayoutDocumentNumber , ImageLayoutFrameLeft , ImageLayoutFrameTop , ImageLayoutFrameRight , ImageLayoutFrameBottom , ImageLayoutPageNumber , ImageLayoutFrameNumber , etc.
  • Call CancelAllPendingTransfers() to cancel all the rest of the transfers.

OnSourceUIClose

Syntax

/**
 * This event is triggered when the user interface of the data source is closed manually by the user.
 */
RegisterEvent('OnSourceUIClose',function() {});

getCapabilities

Syntax

/**
 * Gets detailed information about all capabilities of the current data source.
 * @param successCallback A callback function that is executed if the request succeeds.
 * @param failureCallback A callback function that is executed if the request fails.
 * @argument capabilityDetails Detailed information about the specified capabilities.
 * @argument errorCode The error code.
 * @argument errorString The error string.
 */
getCapabilities(
    successCallback: (capabilityDetails: CapabilityDetails[]) => void,
    failureCallback: (
        errorCode: number,
        errorString: string
    ) => void
): void;

/**
 * Detailed information about a specific capability
 */
interface CapabilityDetails {
    /**
     * The Capability.
     */
    capability: ValueAndLabel;
    /**
     * The container type of the Capability
     */
    conType: ValueAndLabel;
    /**
     * The index for the current value of the Capability
     */
    curIndex: number;
    /**
     * The current value of the Capability
     */    
    curValue: ValueAndLabel;
    /**
     * The index for the default value of the Capability
     */    
    defIndex: number;
    /**
     * The operation types that are supported by the Capability. Types include {"get", "set", "reset" "getdefault", "getcurrent"}
     */   
    query: string[];
    /**
     * The value type of the Capability. Value types include
        TWTY_BOOL: 6
        TWTY_FIX32: 7
        TWTY_FRAME: 8
        TWTY_INT8: 0
        TWTY_INT16: 1
        TWTY_INT32: 2
        TWTY_STR32: 9
        TWTY_STR64: 10
        TWTY_STR128: 11
        TWTY_STR255: 12
        TWTY_UINT8: 3
        TWTY_UINT16: 4
        TWTY_int: 5
     */    
    valueType: ValueAndLabel;
    /**
     * The available values of the Capability
     */    
    values: ValueAndLabel[];
}

interface ValueAndLabel {
    /**
     * Numeric representation of the item
     */
    value: Dynamsoft.EnumDWT_Cap | Dynamsoft.EnumDWT_CapType | Dynamsoft.EnumDWT_CapValueType | number;
    /**
     * Label or name of the item
     */    
    label: string;
}

Usage notes

Check out the Enumerations


setCapabilities

Syntax

/**
 * Sets up one or multiple capabilities in one call.
 * @param capabilities A object that describes how to set capabilities.
 * @param successCallback A callback function that is executed if the request succeeds.
 * @param failureCallback A callback function that is executed if the request fails.
 * @argument capabilities The capabilities to set.
 */
setCapabilities(
    capabilities: Capabilities,
    successCallback: (capabilities: Capabilities) => void,
    failureCallback: (capabilities: Capabilities) => void
): void;

interface Capabilities {
    /**
     * Whether to "ignore" or "fail" the request if an exception occurs. This is an overall setting that is inherited by all capabilities. 
     */
    exceptition: string;
    /**
     * Specifies how to set capabilities
     */
    capabilities: CapabilitySetup[]
}

interface CapabilitySetup {
    /**
     * Specify a capability
     */
    capability: Dynamsoft.EnumDWT_Cap | number;
    /**
     * The value to set to the capability or the value of the capability after setting.
     */
    curValue: number | string;
    errorCode?: number;
    errorString?: string;
    /**
     * Whether to "ignore" or "fail" the request if an exception occurs when setting this specific capability.
     */
    exception? : string;
}

Usage notes

To make things easier, Dynamsoft designed the API with a simplified parameter Capabilities which only requires the minimum information for setting a capability: a number to specify the capability and the value to set to it. Underneath, Dynamsoft takes care of container type setting, value type setting as well as data validation.

Pay attention to the argument you set to the overall parameter exception and the individual parameter exception for each capability. If the overall parameter is set to fail , the setting will abort as soon as an exception is raised while setting any of the capabilities. Otherwise, ignore means to carry on setting the next capability even when the previous one failed. Aside from the overall parameter, the individual exception is optional but takes precedence if set. In other words, you can set the overall exception to ignore and then set the individual one to fail for the capabilities which you think are important. This way, you get notified if these important capabilities failed to be set while other less-important ones are ignored when setting them failed.

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