Image acquisition cards used for multimedia and those used for machine vision are somewhat similar: both acquire images and convert them into digital images that computers can process. However, they are actually quite different.
Multimedia image capture cards acquire images for video and audio editing, and the large data streams generated must be efficiently displayed, stored, and transmitted. Video transmission does not require large amounts of data; a typical method is the use of low-resolution images and compression techniques, which results in a decrease in image quality.
Images used for machine vision must represent the actual object as accurately as possible. An application needs to tell the user precise information, such as that a certain height value should be 5.20 mm.
From the perspective of driver software, multimedia image acquisition cards mostly use existing standard interfaces such as MCI or TWAIN; while image acquisition cards in the field of machine vision, simple acquisition cards can be obtained through registers or according to a more advanced concept, along with driver libraries, which contain the acquisition card register structure and provide direct access to hardware resources.
This reflects the lack of certain features in machine vision hardware standards, such as triggering mechanisms. While the interface between drivers and applications is generally standardized, machine vision applications vary greatly, with many being application-specific and others supported by general-purpose development kits.
