JPS6441591A - Predictive coding device - Google Patents

Abstract

PURPOSE:To reduce the number of codes to be generated by counting a distance up to the first prediction non-coincidence picture element of the next prediction coincidence rate group when the prediction of the last picture element of a certain prediction coincidence rate group coincide to prediction error columns which are classified into groups by the degree of a prediction coincidence rate and rearranged in a scanning line unit. CONSTITUTION:A predicting part 11 predicts the value (1 or 0) of an original picture element to be paid attention to from the value of a peripheral picture element and outputs the value along with a prediction result (d) and a prediction coincidence rate (h). A prediction comparing part 12 compares the prediction result (d) with the value of an original picture element (a) and outputs, as a prediction error (e), a numeric value 0 at the time of a coincidence, and a numeric value 1 at the time of a non-coincidence. A prediction error rearranging part 13 classifies the prediction error (e) into the group in which the prediction coincidence rate is high and the group in which the prediction coincidence rate is low in the scanning line unit, gathers the groups equal to one another and outputs a rearrangement error (f). A run counting part 14 counts the distance between the non-coincidence picture elements of the rearrangement error (f) and outputs a run length (r). An encoding part 15 encodes the run length (r) by an encoding expression for the prediction coincidence rate group to which the head prediction error to compose respective run lengths belongs, and outputs a code (i) and a code clock (j).