PIPE (Pipelined Image-Processing Engine)

Abstract

The Sensory-Interactive Robotics Group of the National Bureau of Standards' Industrial Systems Division is designing and constructing an experimental multistage pipelined image-processing device for research in machine vision. The device can acquire images from a variety of sources, such as analog or digital television cameras, ranging devices, and conformal mapping arrays. It can process sequences of images in real time, through a serial pipeline of local operations, under the control of an external device. Its output can be presented to such devices as monitors, robot vision systems, iconic-to-symbolic mapping devices, and image-processing computers. In addition to a forward flow of images through successive stages of operations in the pipeline, other paths between the stages of the device permit recursive operations within a single stage, and feedback of the results of operations from a stage to the preceding stage. This architecture facilitates a variety of relaxation operations, interactions of images over time, and other interesting functions. Numerous operations are supported, including arithmetic and Boolean neighborhood operations on images within each stage, and between-stage operations on each pixel such as thresholding, Boolean and arithmetic operations, functional mappings, and a variety of functions for combining pixel data converging via the multiple image paths. The device can also be used to implement several alternative processing modes. Some operate within each stage, for example, to control edge effects or to implement “MIMD” operations specific to regions of interest defined by the host device. Others operate between stages, for example, to support variable-resolution pyramids.