People are often confused about what machine vision can and cannot do for a manufacturing line or process. Understanding how it works can help make decisions about if it will resolve problems with the application. So exactly what is machine vision, and how does it work?
Machine vision is the use of a camera or multiple cameras to inspect and analyze objects automatically, usually in an industrial or production environment. The data acquired then can be used to control a process or manufacturing activity. A typical application might be on an assembly line; after an operation is performed on a part, the camera is triggered to capture and process an image. The camera may be programmed to check the position of something, its color, size or shape, or whether the object is there or not. It also can look at and decipher a standard or 2-D matrix barcode or even read printed characters.
Figure 1: A discrete diffuse photoelectric sensor says if a value is measured or not. Courtesy: Frank Lamb, Automation Primer