Video encoding method and decoding method, apparatuses therefor, programs therefor, and storage media for recording the programs

摘要

A video encoding method, in which a video signal consisting of two or more signal elements is targeted to be encoded, includes a step of setting a downsampling ratio is set for a specific signal element in a frame, in accordance with the characteristics in the frame; and a step of generating a target video signal to be encoded, by subjecting the specific signal element in the frame to downsampling in accordance with the set downsampling ratio. The frame may be divided into partial areas in accordance with localized characteristics in the frame; and a downsampling ratio for a specific signal element in these partial areas may be set in accordance with the characteristics in each partial area.

主权项

1. A video encoding method in which a video signal made up of two or more signal elements is targeted for encoding, comprising:
a step of setting a downsampling ratio for a specific signal element of a frame in accordance with a size of an amount of transition within the frame by storing the downsampling ratio in a memory of a video encoding apparatus; a step of generating a video signal which is targeted for encoding by using said video encoding apparatus to downsample the specific signal element inside the frame in accordance with the set downsampling ratio stored in said memory; a step of appending information showing whether or not each block of a specific size includes a significant coefficient to each block for each signal element quantized by said step of generating the video signal targeted for encoding; and a step of setting position information showing the position of a group of blocks which includes the specific signal element within a set of groups of blocks which share the specific signal element, for each set of groups of blocks.