Coding control system of binary picture signal

Abstract

Abstract PURPOSE:To code a binary dither picture by using a pattern of a dither matrix period so as to attain forecasting and switching a document picture and an intermediate tone picture so as to increase the compression rate even to a picture where the document and intermediate tone picture exist in mixture. CONSTITUTION:A dither picture signal (a) mixed with the document and intermediate picture from an input terminal 3 of a dither picture signal of a coding control system of a binary picture signal is fed to a ROM 6 via shift registers 4, 5. Further, a line number from an input terminal 12 of a line number and a history signal (h) from a register 7 are fed to the ROM 6 as an address. The ROM 6 and a register 7 detect whether a specific pattern appearing easily in the pattern comprising plural picture elements appears in the signal (a) or not. Further, the output of the register 4 is fed to a variable length coder 8 and an MH coder 9, and forecast coding is applied by the gradation given to the pattern by the coder 8. Outputs of the register 7 and the coders 8, 9 are fed to a multiplexer 10 to switch the document and intermediate tone pictures thereby applying coding to the binary dither picture.

Inventors

• 👤 Shigeru Yoshida
• 👤 茂 吉田
• 👤 Yoshiyuki Okada
• 👤 佳之 岡田
• 👤 Toru Sato
• 👤 透 佐藤

Bibliographic Details