Abstract: An adaptive predictive encoding apparatus generates predictive values P.sub.1, P.sub.2, . . . , P.sub.n with respect to a quantized value X of a picture element x. Predictive error signals Y.sub.1, Y.sub.2, . . . , Y.sub.n are obtained from the quantized value X and the predictive values P.sub.1, P.sub.2, . . . , P.sub.n. A prediction selection circuit determines the number of mis-predictions from each of the predictive error signals for scanned picture elements. A selection signal M is produced indicating the prediction error signal Y with the least number of mis-predictions, the selection signal controlling a selector to provide the prediction error signal Y in response to the selection signal M. The selected predictive error signal Y is encoded to produce an encoded signal. An adaptive predictive decoding apparatus which decodes the encoded selected predictive error signal is also disclosed.

Abstract: A digital facsimile system suitable for the facsimile transmission of newspaper pages having screened picture portions and printed character portions is disclosed. The transmitter receives a digitized facsimile signal which is a train of pel codes formed by scanning a picture to be transmitted. In response to the digitized facsimile signal, a first reference generator produces first pel codes neighboring the present pel code, a second pel code spaced by the pitch of the screened picture from the present pel code, and third pel codes neighboring the second pel code. A ROM is addressed by the first, second and third pel codes to produce a first prediction code for the present pel code. The output of the ROM and the digitized facsimile signal are supplied to an Exclusive OR which provides a prediction error code according to the difference between the first prediction code and the present pel code. A train of prediction errors codes constitutes a prediction error signal which is encoded and transmitted.