Digitale Vorrichtung zum Kodieren/Dekodieren unter Verwendung von Codes mit variablen Lauflängen

摘要

In a digital coding apparatus or a digital coding and decoding apparatus for image data compression and expansion by means of Huffman coding, a Huffman coding circuit converts a combination of ZERO RUN and VALUE into a variable-length code. A code length calculation circuit has an AC code length table for prestoring variable-length codes and their code lengths in corresponding relationship. The code length calculation circuit inputs not a ZERORUN-VALUE combination but a variable-length code from the Huffman coding circuit, thereby calculating from the variable-length code inputted its code length according to the AC code length table. <MATH>