Biomimetic Vision Sensors - Engineered Biomimicry - page 1

CHAPTER

1

Biom imetic Vision Se nsors

Cameron H.G. Wright and Steven F. Barrett
Department of Electrical and Computer Engineering, University of Wyoming,
Laramie, WY 82071, USA

Prospectus
This chapter is focused on vision sensors based on
both mammalian and insect vision systems. Typically,
the former uses a single large-aperture lens system
and a large, high-resolution focal plane array; the
latter uses many small-aperture lenses, each coupled
to a small group of photodetectors. The strengths
and weaknesses of each type of design are dis-
cussed, along with some guidelines for designing
such sensors. A brief review of basic optical engineer-
ing, including simple diffraction theory and mathe-
matical tools such as Fourier optics, is followed by
a demonstration of how to match an optical system
to some collection of photodetectors. Modeling and
simulations performed with tools such as Zemax and
MATLAB® are described for better understanding of
both optical and neural aspects of biological vision
systems and how they may be adapted to an artificial
vision sensor. A biomimetic vision system based on
the common housefly, Musca domestica , is discussed.

1.1 INTRODUCTION

Biomimetic vision sensors are usually defined as
imaging sensors that make practical use of what
we have learned about animal vision systems.
This approach should encompass more than just
the study of animal eyes, because, along with
the early neural layers, neural interconnects, and
certain parts of the animal brain itself, eyes form
a closely integrated vision system [1-3] . Thus, it
is inadvisable to concentrate only on the eyes in
trying to design a good biomimetic vision sen-
sor; a systems approach is recommended [4] .
This chapter concentrates on the two most
frequently mimicked types of animal vision sys-
tems: ones that are based on a mammalian cam-
era eye and ones that are based on an insect
compound eye. The camera eye typically uses a
single large-aperture lens or lens system with a
relatively large, high-resolution focal plane
array of photodetectors. This is similar to the eye
of humans and other mammals and has long
been mimicked for the basic design of both still
and video cameras [1, 3, 5] . The compound eye

Keywords
Apposition, Biomimetic, Camera eye, Compound
eye, Fly eye, Hyperacuity, Lateral inhibition, Light
adaptation, Mammal eye, Motion detection, Multi-
aperture, Multiple aperture, Neural superposition,
Optical flow, Optical superposition, Photoreceptor,
Retina, Single aperture, Vision sensor