The SIR process is repeated for the next sets of blocks using all the previously decoded sets, thus benefitting more and more from the video frame's spatial correlation.
The previously decoded sets of blocks are used to improve the quality of the side information that is then used for decoding the current set.
As residual, the difference between the previously decoded frame and the fused SI is used.
Assuming that band b k, with k > 0, is being decoded (b0 indicates the DC coefficient) and that the decoding follows a zig-zag scan order, the previously decoded bands b l, l < k can be used to guide the fusion for each SI DCT coefficient.
(b) Obtaining of SI (y k ) by interpolating the previously decoded PCM signals.
The conventional BPSI translational motion branch targets the creation of block-level SI candidates as follows: 1. Backward ME - Using both (previously decoded) reference frames, motion estimation with 16 × 16 block sizes and full pixel accuracy is performed for the forward direction, i.e., from the forward/future reference frame, X f, to the backward/past reference frame, X b.
Backward ME - Using both (previously decoded) reference frames, motion estimation with 16 × 16 block sizes and full pixel accuracy is performed for the forward direction, i.e., from the forward/future reference frame, X f, to the backward/past reference frame, X b.
Typically, the previous and next key frames of the current WZ frame are used for SI generation, although some works use two previously decoded frames [30].
If a larger GOP size is used, previously decoded WZ frames are also used as reference frames while still using only the two neighboring reference frames; these neighboring frames are defined as proposed in [9]. 2.
More specifically, we consider the restricted two-way relay channel, i.e., the bidirectional communication is restricted in the sense that the encoders at the two terminals can neither cooperate, nor are they able to use previously decoded information to encode their messages.
