Cf. Chiu et Cy. Wu, THE DESIGN OF ROTATION-INVARIANT PATTERN-RECOGNITION USING THE SILICON RETINA, IEEE journal of solid-state circuits, 32(4), 1997, pp. 526-534
A new rotation-invariant pattern recognition system is proposed and an
alyzed, In this system, silicon retina cells capable of image sensing
and edge extraction are used so that the system can directly process i
mages from the real world without an extra edge detector, The rotation
-invariant discrete correlation function is modified and implemented i
n the silicon retina structure by using the current summation. Simulat
ion results have verified the correct function of the proposed system,
Moreover, an experimental chip to implement the proposed system with
a 32 x 32 cell array has been designed and fabricated in 0.8-mu m n-we
ll CMOS process, Experimental results have successfully shown that the
system works well for the arbitrary orientation pattern recognition.