With the introduction of CMOS-based image sensors, camera manufacturers have introduced products with ever increasing frame rates. These include standalone cameras for scientific, ballistics and R&D applications and lower cost cameras with high-speed camera-to-computer interfaces targeted at machine vision applications. While standalone cameras may include on-board processors and memory and are relatively expensive, their less expensive counterparts may only feature rudimentary camera control functions, offloading memory buffering functions to the host computer.
One feature both types of camera have in common, however, is the ability to use region of interest (ROI) windowing techniques to increase the speed of image capture. Previously, when high-speed images were captured by a camera, the camera shutter was synchronized with the strobe. Today, since CCD and CMOS-based cameras incorporate electronic shutters, constant illumination sources can be used instead. However, in constant operation, the illumination source is an inefficient system, since it may only be required to be active for 1% of the time while the camera exposes an image.