Method and apparatus for multiview video encoding based on prediction structures for viewpoint switching, and method and apparatus for multiview video decoding based on prediction structures for viewpoint switching

A multiview video decoding method comprising:

• obtaining a base view image stream and an additional view image stream;
• reconstructing an anchor picture of a base view that is a first random access image and an I-picture type image, by decoding the base view image stream;
• reconstructing an image of the base view that precedes, in a display order, the anchor picture of the base view and follows, in a decoding order, the anchor picture of the base view by decoding the base view image stream, wherein the reconstructing of the image of the base view includes performing motion compensation by referring to an image of the base view in a reference picture buffer, and the image of the base view in the reference picture buffer precedes, in the decoding order, the anchor picture of the base view;
• reconstructing a first anchor picture of an additional view that is a second random access image, wherein the reconstructing of the first anchor picture of the additional view includes performing disparity compensation by referring to the reconstructed anchor picture of the base view, by decoding the additional view image stream;
• determining each of a plurality of images of the additional view in the reference picture buffer to be unused for reference in the additional view, wherein the each of the plurality of images of the additional view precedes, in the decoding order, the first anchor picture of the additional view, according to the reconstructing of the first anchor picture of the additional view;
• and
• reconstructing an image of the additional view that precedes, in the display order, the first anchor picture of the additional view and follows, in the decoding order, the first anchor picture of the additional view, by decoding the additional view image stream, wherein the reconstructing of the image of the additional view includes performing disparity compensation by referring to a reconstructed base view image and performing motion compensation by referring to a reconstructed additional view image except for the each of the plurality of images of the additional view in the reference picture buffer that are determined to be unused for reference,
• wherein the each of the plurality of images of the additional view in the reference picture buffer that are determined to be unused for reference includes a second anchor picture of the additional view.