A miniaturized space-variant active vision system: Cortex-I

We have developed a prototype for a miniaturized, active vision system with a sensor architecture based on a logarithmically structured, space-variant, pixel geometry. The central part of the image has a high resolution, and the periphery has a a smoothly falling resolution. The human visual system uses a similar image architecture. Our system integrates a miniature CCD-based camera, a novel pantilt actuator/controller, general purpose processors, a video-telephone modem and a display. Due to the ability of space-variant sensors to cover large work spaces, yet provide high acuity with an extremely small number of pixels, architectures with space-variant, active vision systems provide a potential for reductions in system size and cost of several orders of magnitude. Cortex-I takes up less than a third of a cubic foot, including camera, actuators, control, computers, and power supply, and was built for a (one-off) parts cost of roughly US $2000. In this paper, we describe several applications that we have developed for Cortex-I such as tracking moving objects, visual attention, pattern recognition (license plate reading), and video-telephone communcications (teleoperation). We report here on the design of the camera and optics (8 × 8 × 8 mm), a method to convert the uniform image to a space-variant image, and a new miniature pan-tilt actuator, the spherical pointing motor (SPM), (4 × 5 × 6 cm). Finally, we discuss applications for motion tracking and license plate reading. Potential application domains for systems of this type include vision systems for mobile robots and robot manipulators, traffic monitoring systems, security and surveillance, telerobotics, and consumer video communications. The long-range goal of this project is to demonstrate that major new applications of robotics will become feasible when small, low-cost, machine-vision systems can be mass produced. We use the term “commodity robotics” to express the expected impact of the possibilities for opening up new application niches in robotics and machine vision, for what has until now been an expensive, and therefore limited, technology.