What is WIA & TWAIN

Reports On (TWAIN & WIA)

Similarities: 

• As long as a driver exists, both are able to acquire images from devices such as a scanner or camera.  For devices like cameras, sometimes the driver is actually WIA but we can access it via the "TWAIN compatibility layer". 
• Acquire images with a dialog. 
• Programmatically set properties of the device and acquire the images programmatically without showing a dialog 
•  Not all capabilities are supported by each device, so you can query the device for the ones that it does support. 

Functions of the TWAIN and WIA scanners
Functions	TWAIN	WIA
1. Scan
Scan from the exposure glass	Yes	Yes
Continuous scanning from the ADF	Yes	Yes
ADF Read-ahead	Yes	Yes
Specify the number of originals to be scanned from the ADF	Yes	Yes
Preview	Yes	Yes
Scan using an application that do not have user interface	Yes	Yes
2. Setting
Driver selection	Yes	Yes
Initial Settings
Unit of Measure: (mm, inch, pixel)	Yes	No
Compression	Yes	No
Deskew	Yes	No
Start from Scanner	Yes	No
Save/Delete Mode	Yes	No
Specify original size
When scanning from the exposure glass	Yes	Yes
When scanning from the ADF	Yes	Yes
Orig.Orientn.	Yes	Yes
Orientation:	Yes	Yes
Scan Settings:
1 Sided	Yes	Yes
2 Sided	Yes	Yes
2 Sided (Top to Top, Top to Bottom)	Yes	No
Resolution	Yes	Yes
Brightness:	Yes	Yes
Contrast:	Yes	Yes
Threshold:	Yes	Yes
Col. /Grad.:
Binary	Yes	Yes
Grey Scale	Yes	Yes
8 Colors	Yes	No
16770K colors (Full color)	Yes	Yes
Gam-Curve:	Yes	No
Eras.Bgrnd:	Yes	No
Advanced
Filter (Filter, Dropout Col.)	Yes	No
Color Matching (ICM:, Inversion)	Yes	No
Save/Delete Scanning Area	Yes	No
Specify original size (specify scan area manually)	Yes	No
Comb./Series	Yes	No
Endorser	Yes	No
3. Properties
General
Diagnosis (Scan test)	No	Yes
Authenticate
User Code:	Yes	Yes
General User Authentication	Yes	Yes
Network Connection
Settings for using a specific scanner	Yes	Yes
SNMP V3 Auth.information	Yes	Yes
Driver version display	Yes	Yes

  

Differences:-

see the difference between WIA and TWAIN

SlN.	TWAIN	WIA
1	Twain uses a dialog created by the device manufacturer. TWAIN dialog will provide more options and advanced control over the device	WIA uses a common dialog for all devices that means it is does not provide more option and advance control over the device.
2	TWAIN is supported on all versions of Windows, on Mac OS (8, 9, and X). TWAIN 2.0 early for Linux, Unix, and 64-bit Windows.	WIA only works on windows ME, XP and Vista and above.
3	TWAIN API supports both WIA-based and Twain based scanners.	WIA applications are guaranteed to be base-level compatible with all WIA-based scanners.
4	TWAIN will support Windows, Linux and Mac OS X using TWAIN drivers.	WIA will support Windows applications such Windows Fax and Scan and Paint without the need for any additional software.
5	TWAIN has three transfer modes (Native, Memory, File).	WIA has only 2 transfer modes (Memory and File).
6	Most TWAIN sources save the settings of a previous scan.	WIA has limited functionality and does not.
7	TWAIN allows you to use custom capabilities that the device manufacturer has created even though they don't exist in the TWAIN specifications.	WIA does not allow you to custom capabilities that device manufacturer has created or provided.
8	TWAIN supports options for each page when scanning in duplex mode.	WIA uses the same setting for both sides when we are scanning in duplex mode.
9	TWAIN API is designed for use by C/C++ programmers. Familiarity with the Windows GUI and Component Object Model (COM) interfaces is required.	The WIA API is designed for use by C/C++ programmers. Familiarity with the Windows GUI and Component Object Model (COM) interfaces is required.
10	TWAIN provide an open, multi-platform solution to interconnect the needs of raster input devices with Application software.	Network connected imaging devices that support Web Services for Devices (WSD) protocol can also be used from WIA-compliant imaging applications on Windows Vista and Windows 7 out of the box via a WSD-WIA class driver that shipped as part of Windows Vista.
11	TWAIN is not concerned with the device layer at all. The Source hides the device layer from the application. The Source provides the translation from TWAIN operations and interactions with the Source’s user interface into the equivalent commands for the device driver.	The class driver converts WIA calls to WSD calls and vice versa and makes already existing WIA applications work with WSD based scanners without any additional driver.
12	Most of the companies supports TWAIN.	List Of Scanner which support WIA- https://support.microsoft.com/en-us/kb/264598

List Of Scanner which support WIA-

Click here to check the list of scanner which support WIA