Shift and rotation invariant photorefractive crystal-based associative memory

Chii-Maw Uang; Wei-Feng Lin; Ming-Huei Lu; Guowen Lu; Mingzhe Lu

doi:10.1117/12.217001

18 August 1995 Shift and rotation invariant photorefractive crystal-based associative memory

Chii-Maw Uang, Wei-Feng Lin, Ming-Huei Lu, Guowen Lu, Mingzhe Lu

Proceedings Volume 2529, Photorefractive Fiber and Crystal Devices: Materials, Optical Properties, and Applications; (1995) https://doi.org/10.1117/12.217001
Event: SPIE's 1995 International Symposium on Optical Science, Engineering, and Instrumentation, 1995, San Diego, CA, United States

Abstract

A shift and rotation invariant photorefractive (PR) crystal based associative memory is addressed. The proposed associative memory has three layers: the feature extraction, inner- product, and output mapping layers. The feature extraction is performed by expanding an input object into a set of circular harmonic expansions (CHE) in the Fourier domain to acquire both the shift and rotation invariant properties. The inner product operation is performed by taking the advantage of Bragg diffraction of the bulky PR-crystal. The output mapping is achieved by using the massive storage capacity of the PR-crystal. In the training process, memories are stored in another PR-crystal by using the wavelength multiplexing technique. During the recall process, the output from the winner-take-all processor decides which wavelength should be used to read out the memory from the PR-crystal.

Citation Download Citation

Chii-Maw Uang, Wei-Feng Lin, Ming-Huei Lu, Guowen Lu, and Mingzhe Lu "Shift and rotation invariant photorefractive crystal-based associative memory", Proc. SPIE 2529, Photorefractive Fiber and Crystal Devices: Materials, Optical Properties, and Applications, (18 August 1995); https://doi.org/10.1117/12.217001

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available