Capture/Image Source

What are the differences between TWAIN and WIA?

TWAIN driver TWAIN is the most widely used protocol for physical document scanners. Almost all scanners in the market come with a TWAIN driver and are supported by TWAIN applications like the Dynamic Web TWAIN SDK.

WIA refers to Windows Image Acquisition, which is the still image acquisition platform in the Windows family that enables imaging/graphics applications to interact with imaging hardware and standardizes the interaction between different applications and scanners.

WIA devices can be used by TWAIN applications like DWT through a TWAIN compatibility layer. This means WIA is not supported natively; therefore, when a device supports both TWAIN and WIA, TWAIN is the better option.

By comparison, WIA can only control a very limited set of general capabilities of the device while TWAIN can control all standard and even custom capabilities of the device. Another thing is that TWAIN has three transfer modes (Native, Memory, File), while WIA only has two (Memory, File).