Machine vision acquires images and reliably creates decisions and information from them on an automated basis. This article is about the “middle stage” of that process which is image analysis. Volumes have been written on this; the article seeks to provide a brief practical overview of some of the common software tools applied to images during typical machine vision solution design. It also strives to follow the advice of “if you can’t explain it simply, you don’t know it well enough” in its presentation.
The run-time machine vision process starts with acquisition of an image which provides reliable contrast of the type needed to enable the intended image analysis. Accomplishing this requires designing the illumination, the imaging, and the geometry and interaction between them and the workpiece. Some view this as “lighting up” the workpiece; it’s much more than that; we call it the physics part of the solution. Shortcomings in this process should be resolved rather than relying on image analysis to try to compensate for them.