MOVING IMAGE ENCODING DEVICE, MOVING IMAGE DECODING DEVICE, MOVING IMAGE CODING METHOD, AND MOVING IMAGE DECODING METHOD

摘要

When an encoding mode corresponding to one of blocks to be encoded into which an image is divided by a block dividing part 2 is an inter encoding mode which is a direct mode, a motion-compensated prediction part 5 selects a motion vector suitable for generation of a prediction image from one or more selectable motion vectors and also carries out a motion-compensated prediction process on the block to be encoded to generate a prediction image by using the motion vector, and outputs index information showing the motion vector to a variable length encoding part 13, and the variable length encoding unit 13 variable-length-encodes the index information.

主权项

1. An image decoding device comprising:
a variable length decoding unit for performing variable-length decoding process on coded data multiplexed into a bitstream to obtain compressed data, coding mode and index information, each associated with a coding block, said coding block is obtained by hierarchically dividing an input image according to a maximum block size and an upper limit number of hierarchical layers; a motion compensation prediction unit for performing a motion compensation prediction process on said coding block based on said coding mode to generate a prediction image using a motion vector selected from one or more selectable motion vector candidate, said motion compensation prediction unit selecting said motion vector indicated by said index information; and a decoded image generating unit for generating decoded image data by adding a difference image which is obtained by decoding said compressed data and said prediction image generated by said motion compensation prediction unit; wherein said motion compensation prediction unit selects a spatial motion vector which is obtained from a decoded block located around said coding block or a temporal motion vector which is obtained from a decoded picture which can be referred to by said coding block according to said index information.