The Environmental Research Institute of Michigan (ERIM) has developed the fourth generation of its cellular image processing systems, known as Cytocomputers®. These systems have been developed over the past nine years, primarily for image analysis and machine vision. Other applications have been demonstrated in image enhancement, computer aided design, and signal processing. The new system utilizes the well-proven and mathematically supported neighborhood processing stages with modules for image storage, multiple-image combinations and high-speed image transfer. These modules support the cellular processor stages in an open, extendable architecture which allows enhancement through the addition of modules optimized for particular transformations. This paper first discusses the special requirements of machine vision and image analysis systems and the types of operations required. Next, an overview of the alternative architectures for image processors is presented, along with a discussion of the tradeoffs and criteria which must be weighed in system design. Finally, the new system is described and examples of its operation are discussed.