Image coding apparatus and image decoding apparatus

摘要

An image coding apparatus which outputs a coded bit stream of moving pictures comprises: a plurality of frame memory groups (43, 44) for storing, individually for a plurality of objects which construct a screen, decoded images of the objects in the past; an image storage controller (35) for selecting, in response to a control signal, a frame memory from a predetermined one of said plurality of frame memory groups (43, 44) into which a decoded image is to be written; a motion compensation prediction unit (21) for selecting one of forward direction prediction, backward direction prediction, bidirection prediction and background prediction in individual objects using reference images read out from frame memories of said plurality of frame memory groups (43, 44) provided for the individual objects to perform motion compensating prediction; a subtractor (2) for calculating a difference between the predicted image and a current image to calculate a prediction error image; an adding unit (8) for adding the predicted image from the reference images and the prediction error image of the current image; and a variable length coding unit (17) for variable length coding information. <IMAGE>