Browsing by Author "Chen Yu-Ta"

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Gray code encoding and decoding method applied to holographic storage devices
(2012-06-12)
Ou-Yang Mang
;
Chen Yu-Ta
;
Sun Ching-Cherng
;
Yang Tsung-Hsun
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.
Gray level weighting centroid method for holographic data storage
(2012-10-16)
Ou-Yang Mang
;
Chen Yu-Ta
A gray level weighting centroid method for holographic data storage is disclosed. Firstly, a first gray level image having a plurality of blocks is received. Then, a convolution calculation is performed on a weight matrix and the image, so as to obtain a second gray level image having a plurality of blocks each having a gray level value. The gray level values are divided into a bright gray level value and a dark gray level value by a threshold value, so as to convert the second gray level image into a thresholding image and find the positions of the borders of the blocks corresponding to the bright gray level value. Next, the blocks surrounded by the positions of the borders and respectively used as a centroid block are found by making the positions of the borders correspond to the first gray level image. Finally, the centroid block is calculated to obtain a centroid point.
Method to determine fiducial point for holographic data storage
(2014-08-19)
Ou-Yang Mang
;
Chen Yu-Ta
A method to determine a fiducial point for holographic data storage is disclosed, which utilizes a gray-level frame to sequentially retrieve a regional image used as a retrieved image with the size equal to that of the frame from a received gray-level image. The gray-level frame is compared with each retrieved image to obtain a plurality of values and construct a 2D proto-matrix. The 2D proto-matrix is transformed into a 2D matrix via letting the values smaller than 0 be 0. The 2D matrix and a retrieving matrix, which has a dimensionality equal to or smaller than that of the frame, are used to obtain an anchor matrix. A greatest value in the central region of the 2D matrix is found to function as an anchor value according to the anchor matrix, thereby find a fiducial point in the gray-level image.
METHOD TO DETERMINE FIDUCIAL POINT FOR HOLOGRAPHIC DATA STORAGE
(2013-04-04)
OU-YANG Mang
;
Chen Yu-Ta
A method to determine a fiducial point for holographic data storage is disclosed, which utilizes a gray-level frame to sequentially retrieve a regional image used as a retrieved image with the size equal to that of the frame from a received gray-level image. The gray-level frame is compared with each retrieved image to obtain a plurality of values and construct a 2D proto-matrix. The 2D proto-matrix is transformed into a 2D matrix via letting the values smaller than 0 be 0. The 2D matrix and a retrieving matrix, which has a dimensionality equal to or smaller than that of the frame, are used to obtain an anchor matrix. A greatest value in the central region of the 2D matrix is found to function as an anchor value according to the anchor matrix, thereby find a fiducial point in the gray-level image.