Video encoding method and decoding method, apparatuses therefor, programs therefor, and storage media which store the programs

摘要

A video encoding method for generating, based on disparity information between an already-encoded reference camera image and an encoding target camera image corresponding to the reference camera image, a disparity-compensated image by means of inter-camera image prediction; and encoding a differential image between the encoding target camera image and the disparity-compensated image. The method includes selecting, for each predetermined section unit on the differential image, one of a decoded differential image group obtained by decoding a differential image between the already-encoded camera image and the disparity-compensated image and a decoded camera image group obtained by decoding the already-encoded camera image, by determining whether or not there is a disparity-compensated image at the corresponding position, that is, whether or not the corresponding pixel in the disparity-compensated image has an effective value.

主权项

1. A video encoding method of encoding a multi-viewpoint video image by using disparity compensation, the method comprising the steps of:
generating, based on disparity information between a reference camera image, which is obtained by decoding an already-encoded camera image, and an encoding target camera image corresponding to the reference camera image, a disparity-compensated image for the encoding target camera image; setting reference target information, which indicates a reference image group as the reference target, for each predetermined section unit on the encoding target camera image in accordance with a state of the disparity-compensated image; selecting, for each predetermined section unit on the encoding target camera image, one of a decoded differential image group, which includes decoded differential images, each obtained by decoding an already-encoded differential image between a camera image and a disparity-compensated image, and a decoded camera image group, which includes decoded camera images, each obtained by decoding an already-encoded camera image, as the reference target based on the set reference target information, where the decoded differential images and the decoded camera images each have the same view point as that of the encoding target camera image; predictive-encoding a differential image between the encoding target camera image and the disparity-compensated image by referring to a reference image included in the image group selected as the reference target; storing a decoded differential image, which is obtained by decoding the encoded differential image, as a constituent of the decoded differential image group; and storing a decoded camera image, which is obtained by decoding the encoding target camera image, which was already encoded, based on the decoded differential image, as a constituent of the decoded camera image group, wherein in the step of setting the reference target information, the reference target information is set in accordance with presence or absence of the disparity-compensated image; and in the step of selecting one of the decoded differential image group and the decoded camera image group, when the reference target information indicates that the disparity-compensated image is present, the decoded differential image group is selected, and when the reference target information indicates that the disparity-compensated image is absent, the decoded camera image group is selected.