RU2226043C1 - Method for compression and recovery of messages - Google Patents

Abstract

FIELD: electrical communications. SUBSTANCE: random square matrix is identically generated on sending and receiving ends. Then other matrix is shaped from fixed half-toned video image which is transformed to digital form by representing it in the form of product of three matrices (rectangular matrix, size Nxm, random square one, size mxm, and rectangular matrix, size mxN). These matrices are transferred to digital communication channel. Messages are recovered in reverse sequence. Then fixed half-toned video image is shaped from matrix obtained. Method is suited in particular to transfer video data over low- frequency digital communication channels. EFFECT: enhanced data transmission speed at same quality of message recovery. 3 cl, 14 dwg

Description

Description text in facsimile form (see graphic part).

Claims (3)

1. A method of compressing and restoring messages, which consists in the fact that previously on the transmitting and receiving sides they identically generate a random square matrix of size m × m elements, random rectangular matrices are generated from single and zero elements of size N × m and m × N elements, transform random rectangular matrices of size N × m and m × N elements by dividing the elements of each row of a random rectangular matrix of size N × m elements by the sum of the units of the corresponding row and dividing the elements of each column by of a rectangular tea matrix of size m × N elements by the sum of units of the corresponding column, a matrix of size N × N elements is calculated by multiplying the resulting rectangular matrix of size N × m obtained by converting to a random square matrix of size m × m and the resulting rectangular matrix of size m × m N elements, sequentially invert each element of random rectangular matrices of size N × m and m × N elements, repeatedly transform random rectangular matrices of size N × m and m × N elements, repeat o calculate a matrix of N × N elements by successively multiplying the rectangular matrix of N × m elements obtained after the transformation, a random square matrix of m × m elements and obtained after the transformation of a rectangular matrix of m × N elements, subtract the sum of the squares of the difference from the same amount, obtained in the previous step and, in the case of a positive difference, save the inverted value of the element, and otherwise, perform its repeated inversion, transmit a set of n and zero elements of rectangular matrices of size N × m and m × N elements over the communication channel, take a set of zero and single elements of rectangular matrices of size N × m and m × N elements from the communication channel, are converted by dividing the elements of each row of a rectangular matrix of size N × m elements by the sum of units of the corresponding row and dividing the elements of each column of a rectangular matrix of size m × N elements by the sum of units of the corresponding column, characterized in that each element of a random square matrix of size m × m e elements belongs to the range -500- + 500, as a message to be compressed and restored, use a stationary halftone video image from which form a matrix of quantized samples of a stationary halftone video image of size M × M elements, convert the matrix of quantized samples of a stationary halftone video image of size M × M elements to digital form, in this case, a matrix of coefficients of a two-dimensional discrete cosine transform of size M × M elements is preliminarily formed by multiplying the matrix of discrete cosine transforms of size M × M elements by a matrix of quantized samples of a stationary halftone video image of size M × M elements and a transposed matrix of discrete cosine transforms of size M × M elements, form a matrix of coefficients of a two-dimensional discrete cosine transform of size N × N elements , based on the expression A (i, j) = L (i, j), where i = 1, 2, ..., N, j = 1, 2, ..., N, L (i, j) - i-th, j-th element of the matrix of coefficients of a two-dimensional discrete cosine transform of size M × M e elements, A (i, j) is the i-th, j-th element of the matrix of coefficients of a two-dimensional discrete cosine transform with the size of N × N elements, and N≤M is selected, the normalizing matrix of the size of N × N elements is identically formed on the transmitting and receiving sides whose elements C (i, j) are calculated by the formula

form a matrix of normalized coefficients of a two-dimensional discrete cosine transform with the size of N × N elements, by multiplying each coefficient A (i, j) by the corresponding element of the normalization matrix of size N × N elements, after calculating the matrix of size N × N elements, calculate the sum of the squares of the differences between matrix elements of size N × N elements and their corresponding matrix elements of normalized coefficients of a two-dimensional discrete cosine transform of size N × N elements, and after repeated subtraction dividing a matrix of N × N elements recalculates the sum of the squares of the differences between the elements of a matrix of N × N elements and the corresponding elements of the matrix of normalized coefficients of a two-dimensional discrete cosine transform of N × N elements, after converting N × m rectangular matrices on the receiving side and m × N elements form a matrix of reconstructed normalized coefficients of a two-dimensional discrete cosine transform of size N × N elements by successive multiplication obtained after the transformation of a rectangular matrix of size N × m, a random square matrix of a size of m × m elements and obtained after conversion of a rectangular matrix of a size m × N elements, form a matrix of reconstructed coefficients of two-dimensional discrete cosine transformation of size N × N elements by dividing the values of each i- of the jth element of the matrix of the restored normalized coefficients of the two-dimensional discrete cosine transform of size N × N elements to the corresponding element of the normalization m Trices of size N × N elements, form a matrix of reconstructed coefficients of a two-dimensional discrete cosine transform of size M × M elements, by assigning the value of each i-th, j-th element of a matrix of reconstructed coefficients of a two-dimensional discrete cosine transform of size N × N elements to each i- mu, jth element of the matrix of the reconstructed coefficients of the two-dimensional discrete cosine transform with the size of M × M elements, and zeros are written as the remaining elements, the matrix of reconstructed squares is formed ntovanyh samples of a stationary grayscale video image by multiplying the transposed matrix of a discrete cosine transform of size M × M elements on a matrix of reconstructed coefficients of a two-dimensional discrete cosine transform of size M × M elements and a matrix of discrete cosine transform of size M × M elements, and represent a matrix of quantized samples a motionless halftone video image of size M × M elements in the form of a motionless halftone video image. 2. The method according to claim 1, characterized in that for the formation of a matrix of quantized samples of a stationary halftone video image of size M × M elements for each of its elements S (x, y), where x = 1, 2, .., M; y = 1, 2, ..., M, is assigned a quantized value of the corresponding pixel of a stationary grayscale video image. 3. The method according to claim 1, characterized in that for representing a matrix of quantized samples of a stationary halftone video image of size M × M elements in the form of a stationary halftone video image, each pixel of a stationary halftone video image is assigned a value of the corresponding element of the matrix of restored quantized samples of a stationary halftone video image of size M × M elements.

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