TWAIN Scanning and Capturing

TWAIN Scanning / TWAIN Capture: Scanners, Digital cameras, Capture cards

LEADTOOLS provides a powerful set of tools spanning the full spectrum of digital imaging, including in-depth support for image acquisition through industry standard interfaces from a wide variety of hardware devices.

With LEADTOOLS you can control any scanner, digital camera or capture card that has a TWAIN device driver. High-level acquisition support is provided for ease of use, and low-level functionality is provided for flexibility and control in even the most demanding applications.

Using LEADTOOLS TWAIN capabilities, your application can:

• Use the default user interface included with the TWAIN driver.

• Create your own user interface to the driver interface.

• Bypass the interface entirely for completely automated tasks or batch scanning.

• Control the type of image which is acquired (black & white, b/w with halftone, grayscale, color - as supported by the device).

• Control the resolution (dpi), position , size, and orientation of the image to be acquired.

• Use the Automated Document Feeder for single and multi-page scans, including support for duplex scanning.

• Use supplied events and callbacks to code your own special per-page processing

• Use selection dialogs to allow selection of TWAIN source, or select among multiple TWAIN sources in code.

• Use of native, buffered memory or file transfer modes when acquiring from a TWAIN device.

• Flexibility to get and set all TWAIN v2.0 capabilities that the device's TWAIN driver supports.

• Save of the device's TWAIN capability settings to a template file, helping to save multiple settings of sources and load them as needed.

• Buffered memory transfer mode includes compression support. The scan data is compressed using JPEG, RLE, BITFIELDS, GROUP 3, GROUP 4 or PACKBITS to reduce the data transfer bottle neck.

• Perform the save of the Memory Buffered Transfer data directly to a file.

• Get the Extended Image Info that some TWAIN scanner drivers support. For example, if the scanner driver supports reading barcodes or patch codes, then that information could be retrieved via LEADTOOLS TWAIN support.

• Access digital cameras using TWAIN. LEADTOOLS provides the functionality to negotiate a TWAIN file system, used for accessing digital cameras, with the following:

• Change Directory

• Create Directory

• Delete

• Format Media

• Close File

• Get First File

• GetInformation

• Get Next File

• Rename

• Copy

• Automatic Capture Directory

• Get and set TWAIN  JPEG compression. LEADTOOLS provides the functionality to describe the information necessary to transfer a JPEG-compressed image during a buffered transfer. Images compressed in this fashion will be compatible with the JPEG File Interchange Format, version 1.1. The following TWAIN messages are implemented:

• DG_IMAGE / DAT_JPEGCOMPRESSION / MSG_GE

• DG_IMAGE / DAT_JPEGCOMPRESSION / MSG_GETDEFAULT

• DG_IMAGE / DAT_JPEGCOMPRESSION / MSG_RESET

• DG_IMAGE / DAT_JPEGCOMPRESSION / MSG_SET

• Negotiate the most frequently used capabilities with TWAIN high-level functions with no need to go to basic set/get capability functions to set/get their capabilities. These functions negotiate the following capabilities:

• ICAP_XFERMECH

• ICAP_IMAGEFILEFORMAT

• ICAP_COMPRESSION

• ICAP_XRESOLUTION

• ICAP_YRESOLUTION

• ICAP_FRAMES

• ICAP_UNITS

• ICAP_BITDEPTH

• ICAP_BRIGHTNESS

• ICAP_CONTRAST

• ICAP_HIGHLIGHT

• ICAP_ORIENTATION

• ICAP_SUPPORTEDSIZES

• DG_IMAGE / DAT_RGBRESPONSE / MSG_RESET

• DG_IMAGE / DAT_RGBRESPONSE / MSG_SET

• CAP_INDICATORS

• CAP_DUPLEXENABLED

• CAP_DUPLEX

• CAP_XFERCOUNT

Using LEADTOOLS FAST TWAIN capabilities, your application can:

• Determine the best and fastest scan configuration for your TWAIN scanner based on the scanners capabilities for transfer mode, compression, buffer size, and image data format.

• Save the best configuration for later use.

• Use the best configuration so that the images will be acquired as fast as possible.

• Get default scan configurations based on the transfer mode, bits per pixel and number of buffers.

With the LEADTOOLS TWAIN support, you can do anything that your TWAIN v2.0 driver supports. If your TWAIN driver is not v2.0 or does not support a functionality listed above, then LEADTOOLS will support all of the features that the driver has that are compatible with the TWAIN v2.0 specification.

LEADTOOLS TWAIN support gives your applications access to the wide variety of devices which can acquire images via TWAIN from manufacturers like Kodak, Hewlett Packard, Microtek, Logitech, Fuji and many more.

Supported Platforms

TWAIN C DLL

TWAIN ActiveX (OCX)

TWAIN COM

TWAIN C++ Class Library

TWAIN .NET and COM Interop