Introduction

This joint effort between Distant Focus Corporation and Dr. Mark Neifeld of the University of Arizona was supported by the Microsystems Technology Office (MTO) office within DARPA. (Program manager – Dr. Ravindra Athale). The program was originally called the Integrated Computational Imaging System (ICIS) and was the prelude to the MONTAGE program.

Multiple Aperture Vision Systems

Image courtesy of the Institute of Medical Sciences at the University of Aberdeen

We are all familiar with the conventional single aperture camera, a design that has served society's photographic needs for well over a century. However, nature provides numerous examples of creatures that rely on multiple aperture vision systems. For example, the compound eye of a dragonfly contains over 30,000 lens enabling it to gather detailed information from its surroundings. Is there an advantage to this format? Obviously, transferring the dimensions of this system to a camera would open opportunities previously unexplored.

The nature of this investigation is to implement a distributed imaging algorithm, that is, to fuse images obtained from a set of low resolution sensors in order to obtain a higher resolution view of a scene. With this multiple aperture platform we examined the issues of building a practical system and investigated how visual performance is enhanced.

Distributed Imaging Demonstration Platform

The camera array contains 129 monochrome digital CMOS image sensors controlled by a PC104 computer. Fifty-nine of the image sensors have a 5.6mm focal length lens attached. The algorithm is run from a remote workstation/laptop that uses a TCP/IP network connection to transfer control and data information. The PC104 computer and its interface to the 32 acquisition boards is located behind the central plate.

Using this platform, we have demonstrated enhanced resolution, that is, the resolution of the composite image exceeds that of the individual sensors. The system also displays foveation, regions of higher resolution that are user selectable.

The platform illustrates three important new features:

• Integrated imaging and processing systems provide features that can not be readily achieved in a conventional package. (Enhanced resolution and foveation)
• The aspect of the camera framework can be built much flatter, allowing even conformal designs.
• Large numbers of integrated, inexpensive sensors can provide performance that exceeds a higher cost, single element solution.