Smart Camera

Smart Camera

Although there are many definitions of smart cameras offered by the media, camera manufacturers and developers, still no binding definition exists. In a field where terms are often defined by their predominant usage, most material in this article is based on the term's most predominant usage. In the book "Smart Cameras", a smart camera is defined as a vision system which, in addition to image capture circuitry, is capable of extracting application-specific information from the captured images, along with generating event descriptions or making decisions that are used in an intelligent and automated system.

A smart camera or "intelligent camera" is a self-contained, standalone vision system with built-in image sensor in the housing of an industrial video camera. It contains all necessary communication interfaces, e.g. Ethernet, as well as industry-proof 24V I/O lines for connection to a PLC, actuators, relays or pneumatic valves. It is not necessarily larger than an industrial or surveillance camera. "Having" a capability in Machine Vision generally means a degree of development such that these capabilities are ready for use on individual applications.

This architecture has the advantage of a more compact volume compared to PC-based vision systems and often achieves lower cost, at the expense of a somewhat simpler (or missing altogether) user interface.

Although often used for simpler applications, modern smart cameras can rival PCs in terms of processing power and functionalities. Smart cameras have been marketed since the mid 80s, but only in recent years have they reached widespread use, once technology allowed their size to be reduced while their processing power has reached several thousand MIPS (devices with 1 GHz processors and up to 8000MIPS are available as of end of 2006).

Having a dedicated processor in each unit, smart cameras are especially suited for applications where several cameras must operate independently and often asynchronously, or when distributed vision is required (multiple inspection or surveillance points along a production line or within an assembly machine).

A smart camera usually consists of several (but not necessarily all) of the following components:

• Image sensor (matrix or linear, CCD- or CMOS)
• Image digitization circuitry
• Image memory
• processor (often a DSP or suitably powerful processor)
• program- and data memory (RAM, nonvolatile FLASH)
• Communication interface (RS232, Ethernet)
• I/O lines (often optoisolated)
• Lens holder or built in lens (usually C, CS or M-mount)
• Built in illumination device (usually LED)
• Purpose developed real-time operating system (For example VCRT)

A video output (e.g. VGA or SVGA) may be an option for a Smart Camera.