Method to determine fiducial point for holographic data storage

摘要

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.

主权项

1. A method to determine a fiducial point for holographic data storage, comprising steps:
receiving a gray-level image; using a first reference gray-level frame to sequentially retrieve from said gray-level image regional images each having a same size as said first reference gray-level frame to function as first retrieved images, comparing said first reference gray-level frame with each said first retrieved image to obtain a plurality of first values, and using said first values to construct a first 2D proto-matrix; transforming said first 2D proto-matrix into a first 2D matrix via letting said first values which are smaller than 0 be 0 and keeping unchanged said first values equal to or greater than 0; using said first 2D matrix and a retrieving matrix, which has a dimensionality equal to or smaller than that of said first reference gray-level frame, to obtain a first anchor matrix, and finding a greatest said first value in a central region of said first 2D matrix to function as a first anchor value according to said first anchor matrix; and using said first anchor value to find a first position corresponding to said first anchor value in said gray-level image, and using said first position as a position of a first fiducial point, wherein said gray-level image has a grayscale depth of N bits, and wherein said first value is denoted by V1 and obtained according to an equation:V⁢⁢1=(2⁢μx⁢μyI+C1⁢I)⁢(2⁢σxyI+C2⁢I)(μx2+μyI2+C1⁢I)⁢(σx2+σyI2+C2⁢I) wherein x is said gray-level image and yI is said first retrieved image, wherein 0 wherein said gray-level image has a plurality of blocks, and wherein each said block contains n×n pieces of pixels, and wherein n is a natural number, and wherein retrieving said first retrieved images starts from a first row and a first column of said blocks and advances toward a last row and a last column sequentially pixel by pixel.