Method for coding vector refinement information required to use motion vectors in base layer pictures when encoding video signal and method for decoding video data using such coded vector refinement information

摘要

A method for coding vector refinement information required to use motion vectors in base layer pictures when encoding a video signal and a method for decoding video data using the coded vector refinement information are provided. A value for vector refinement information of an image block present in a frame in an enhanced layer, which represents the difference between a position pointed to by a motion vector of the image block and a position pointed to by a scaled motion vector obtained by scaling a motion vector of a corresponding block in a temporally coincident frame in a bitstream of the base layer by half of the ratio of the enhanced layer picture size to the base layer picture size, is selected from 8 values allocated to 8 quarter-pixels surrounding the position pointed to by the scaled motion vector, and the vector refinement information having the selected value is recorded.