The coding equipment, being the coding equipment which encodes the image which is displayed in the computer reading possible record media null multivalued pixel which records

摘要

PROBLEM TO BE SOLVED: To provide a decoding method having high compressibility and little deterioration of image quality. SOLUTION: A threshold value is determined on the basis of the maxmium value and the minimum value of values of picture elements contained in a picture element block formed by dividing a picture image. By using the threshold value, the picture elements contained in the picture element block are selected and picture element groups are set. An average value of picture elements contained in the picture element group is assigned to the picture elements contained in the picture element group.