This paper proposes an overview of different processing paradigms inherent to image and vision processing, and of hardware support for them. It identifies some still open questions in parallel image/vision processing. The paper is organized into four parts. Part one discusses three main problems inherent to image and vision processing: processing flux parallelism, data parallelism and application constraints. Part two makes an overview of the flux (or control) parallelism hardware support for vision processing. Part three discusses the data parallelism concept and the architectural support for it existing in vision and image architectures. The presentation concludes with a discussion of future requirements for processors. Our conviction is that the future microprocessors, because of technology advances, will progressively integrate the structures of today's parallel dedicated computers.