Duplex modified‐read coding scheme for facsimile transmission of documents
Kiyoshi Tanaka, Yasuhiro Nakamura, Kineo Matsui · Electronics and Communications in Japan (Part I Communications) · 1990
Abstract This paper proposes a new duplex modified‐READ (MR) coding scheme for transmitting a facsimile picture on which other information can be embedded. When the vertical mode on the coding‐scanning line is coded, the MR coding is carried out by moving the run‐length of a black or white pel using the bit‐series of an information source to be duplexed. This method offers a facsimile picture which has almost the same quality as its original without increasing the quantity of the MR‐coding, and can transmit the second information without notice by a third person. For example, the second information with 2 k to 14 kbytes can be transmitted with one of the CCITT test documents. This is an answer to conventional facsimile systems which have a lack of secrecy. This method also contributes to double the transmission rate so that transmission lines can be used more efficiently.