Threshold-free pattern-based low bit rate video coding

Abstract

Pattern-based video coding (PVC) has already established its superiority over H.264 in low bit rate areas because of an extra pattern-mode to segment out the arbitrary shape of the moving region in macroblock. To determine the pattern-mode, the PVC however uses three thresholds which sometimes depend on the content of the video sequences. Thus, the best performance of the PVC may not be achieved using the pattern-mode. In this paper, a novel PVC scheme is proposed which does not use any thresholds to determine the pattern-mode and hence more efficient performance is achieved without knowing the content of the video sequences. In addition, efficient pattern similarity metric and new Lagrangian multipliers are also developed. The experimental results confirm that this new scheme significantly improves the quality compared to the existing PVC as well as H.264 video coding standard.

Pattern based video coding with uncovered background

“…The detailed procedure will be described in Sub-section 2.2. To exploit the nonrectangular MB portioning and partial skipped mode, a pattern mode is incorporated as an extra mode into the conventional H.264 video coding standard, is defined as the PVC scheme [7]. Figure 1 has shown the pattern codebook (PC) [6] comprising 32 patterns which are used in the proposed scheme.…”

“…We also use other two options using the traditional pattern matching with Equation (1) and ME&MC, i.e., using the immediate previous frame (existing pattern matching) and using the McFIS (pattern matching using McFIS) to maximize the rate-distortion performance where a MR is not good matched by the best pattern. Figure 3 (a) compares the average percentages of MBs selected by the LO as the reference MBs for three relevant techniques (i) the existing pattern matching [7] i.e., matching and ME&MC are carried out using immediate previous frame, (ii) pattern matching and ME&MC are carried out using the McFIS, and (iii) pattern matching using the McFIS but ME&MC is carried out using the immediate previous frame. The third technique is the newly introduced pattern matching and ME&MC approach while the second technique is for the multiple reference frame approach.…”

“…Then to find the best matched pattern from the pattern codebook through a similarity metric [7]. ME&MC are carried out using only pattern covered MR (i.e., the white region).…”

“…To exploit the non-rectangular block partitioning and partial block skipping for static background area in an MB, the patternbased video coding (PVC) [5][6] [7] scheme partitions the MBs via a simplified segmentation process that again avoids handling the exact shape of the moving objects, so that the popular MB-based ME could be applied. The PVC algorithm focuses on the moving regions (MRs) of the MBs, through the use of a set of regular 64-pixel pattern templates (see Figure 1).…”

Efficient Low Bit-Rate Intra-Frame Coding using Common Information for 360-degree Video

“…Later, Versatile Video Coding (VVC) [12] has been explored to support more sophisticated video coding which is more or less an evolution of the basic building blocks already adopted in HEVC. However, for low bit rate video transmission, these state-of-the-art methods are still complex enough to meet the limited bit-budget over narrow bandwidth channel while maintaining a good quality with less blocking artifacts [13] [14]. To tackle this, ever better compression is possible for low bit rate scenarios to relieve the storage and transmission burdens by saving bit rates and maintaining the quality of 360-degree contents.…”