IMAGE DATA CODING BY PATTERN MATCHING

In an image coding system, a library of reference patterns is stored for reference and the input pattern is matched with a reference pattern selected from the library to find a best reference pattern. An error map of the input pattern is produced with respect to the best reference pattern and then it is determined whether an error pattern of the error map meets a predetermined criterion which provides a discrimination from an error caused by a pattern difference between the input pattern and the best reference pattern. If the error pattern meets the predetermined criterion, the error pattern is deleted from the input pattern and then the modified input pattern is predictive-coded referring to the best reference pattern.