JPS54150021A - Process system for picture element signal - Google Patents

Abstract

PURPOSE: To secure the process of the picture signals with a high data compression rate and thus to ensure a highly efficient transmission of the signals by applying the run-length encoding method to the black and white part of the picture and then encoding the level directly the level for the picture of intermediate gradation.

CONSTITUTION: Picture image (a) is sampled along scan line AB to secure quadrivalent quantization 60, and thus density histogram (b). As a result, the density level shown in column 2 is obtained in accordance with the picture elements eack shown in column 1 of Chart 50. The picture elements of the level (code 00) showing the white color and the picture elements of the level (code 11) showing the black color are those of G∼J, L, M, O and Q∼T, and this section means the run- length encoding section (column 3 of Chart 50). The picture elements of the level (code 01, 10) showing the intermediate gradation are K, N and P, and this section is that (column 4 of Chart 50) where the density is encoded directly. Accordingly, the information of each element is compressed to the code shown in column 5 of Chart 50 to be transmitted. In this way, the transmission efficiency can be increased.

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