Gray code encoding and decoding method applied to holographic storage devices
AssigneeNational Chiao Tung University
InventorsMang Ou-Yang, Yu-Ta Chen, Ching-Cherng Sun, Tsung-Hsun Yang
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Abstract
A gray code encoding and decoding method applied to holographic storage devices is proposed. The encoding method uses gray levels of a 2D detector to encode a certain amount of original bits of the original data, and then sends them to a spatial light modulator (SLM) for encryption. The decoding method corrects the received gray levels to the original gray levels, and then compares the maximum gray level with the original gray levels to decode the original gray level into binary data. The proposed encoding and decoding method can better make use of storage locations of the 2D detector and get a code rate close to 1.
Claims28
A gray code encoding method applied to holographic storage devices comprising the steps of:
- providing a binary original data having a plurality of original bits;
- adding a first start bit, a second start bit and an end bit into said binary original data to form a bit data array, defining gray levels of said first start bit, said second start bit and said end bit respectively as a first start gray level gray(1), a second start gray level gray(2), and an end gray level wherein gray(1) and gray(2) differ by a certain gray level Δ;
- and
- retrieving a certain amount of said original bits from said original data and performing gray code encoding to said certain amount of said original bits according to said first start bit, said second start bit, said end bit, gray(1), gray (2), and said end gray level.
A gray code decoding method applied to holographic storage devices comprising the steps of:
- defining a maximum gray level, a first start gray level gray(1), and a second start gray level gray(2) with gray(1) and gray(2) differing by a certain gray level Δ;
- receiving a gray level data and correcting said gray level data to original gray levels according gray(1), gray(2), and said maximum gray level;
- decoding said original gray levels into a binary original data according to said maximum gray level by determining said original data to be a binary digit of “1” when said original gray level is larger than a half of said maximum gray level and determining said original data to be a binary digit of “0” when said original gray level is smaller than a half of said maximum gray level.
Dependencies are inferred from the claim text.