Intra prediction is a crucial component of hybrid video coding framework due to its remarkable ability to reduce spatial redundancy in video signals. Unlike the single-mode based intra prediction in HEVC and VVC, intra fusion prediction methods, that combine the results of multiple angular prediction modes, were newly adopted by Enhanced Compression Model (ECM). However, intra fusion prediction over-relies on local spatial correlations and neglects potential texture similarities in non-adjacent regions. To overcome these limitations and elevate the accuracy of luma intra prediction, a Recurrent Intra Prediction Mode (RIPM) is proposed in this paper, which is composed of two sub-modules, i.e., Recurrent Intra Merge Mode (RIMM) and Recurrent Block Vector Substitution Module (RBVSM). RIMM utilizes the recurrent spatial texture information of the adjacent and non-adjacent spaces for adaptive mode derivation and prediction within the intra fusion prediction framework. RBVSM is a sophisticated mechanism for adaptive prediction mode selection and weight assignment during intra fusion prediction, resulting in enhanced coding performance with minimal impact on computational complexity. The proposed method, implemented on top of ECM-12.0, demonstrates a 0.095% BD-rate gain for the luma component under All Intra configuration, with negligible complexity increase. Currently, RIPM is under study in Exploration Experiments (EE) for ECM in JVET.

This paper presents an adaptive bilateral matching technique for decoder-side motion vector refinement in video coding. It allows encoder to choose not only the conventional bilateral matching mode with symmetric motion vector difference but also the asymmetric alternatives. To study the efficiency of the proposed technique, the proposed method is integrated in the Versatile Video Coding Test Model 11.0. The experimental result reports an overall of −2.78% luma Bjontegaard Delta rate for the random-access configurations. The compression efficiency on top of the Enhanced Compression Model that beyond the VVC capability are also reported.

Block-based partitioning is one of the fundamental techniques in video coding. Geometric-based block partitioning is a well-studied method to enable better spatial adaptation to the signal properties. This paper introduces the most recent proposal of advanced geometric-based inter prediction (GIP) made to the state-of-the-art are video coding standard - Versatile Video Coding (VVC). Implemented in the latest test model VTM-6.0 to generalize the existing triangle partition mode (TPM) and evaluated with the Joint Video Experts Team (JVET) Common Test Conditions (CTC) sequences, the proposed advanced GIP scheme provides luma BD-rate reduction of 0.56% for random access (RA) and 1.37% for low-delay (LB) test cases with 2% encoder runtime increase and negligible decoder runtime increase. Furthermore, BD-rate reductions up to 2.92% and 3.49% for RA and LB test cases can be achieved in the absence of multiple related VVC inter prediction tools.

This paper describes the coding block structure used in the joint Qualcomm/Technicolor responses to the JVET call for proposal on video compression with capability beyond HEVC. The proposed block structure relies on the known quadtree plus binary tree (QTBT) block structure and brings some higher degree of flexibility in it. Two sets of partitioning modes extend QTBT: the ternary tree (TT) and the asymmetric binary tree (ABT). The added split modes are used with a normative non-redundancy policy, which ensures any block topology can be reached through a unique series of split modes. Finally, some flexible binary and ternary partitioning is allowed near the bottom and right picture borders. Overall, the proposed split modes, non-redundancy and picture border strategies lead to 19.6% bitrate reduction over HEVC.

In this paper, a MV derivation method based on the idea of frame rate up-conversion (FRUC) is proposed. When a block is signaled as FRUC mode, the motion information of the block is derived without signaling. Moreover, derived MVs are refined at sub-block level for more accurate motion field. In addition, two matching methods, i.e., bilateral matching and template matching are supported to obtain good performance in both bi-directional and uni-directional prediction. Simulations under HEVC common test conditions show that over 4.2% average BD-rate reduction was achieved over HEVC reference software HM-16.6 in the case of random access configuration. The method has been adopted into the Joint Exploration Model (JEM) developed by the joint video exploration team (JVET) of MPEG and ITU-T VCEG for the study of next generation video coding standard.

This paper presents a method for efficient compression of high dynamic range (HDR) and wide color gamut (WCG) video data. The proposed solution consists of two major elements: a conventional video codec (e.g., HEVC) and pre-and post-processing steps applied prior to encoding and after decoding process, respectively. The proposed HDR/WCG video coding system can be configured to provide two configurations: (1) a non-backward compatible bitstream with improved HDR video quality and (2) a SDR backward compatible bitstream with balanced visual quality between the reconstructed signal by the SDR and the HDR receivers. The simulations conducted under the MPEG Common Test Conditions for HDR demonstrate that the compression efficiency of the proposed solution outperforms the anchor solution on objective metrics. Additionally, subjective evaluations conducted under MPEG revealed improved visual quality for the proposed method.

The Discrete Cosine Transform (DCT), and in particular the DCT type II, has been widely used for image and video compression. Although DCT efficiently approximates the optimal Karhunen–Loève transform under first-order Markov conditions with low complexity, the energy packing efficiency is still limited since a fixed transform cannot always capture the highly dynamic statistics of natural video content. In this paper, to further improve the transform efficiency, an Enhanced Multiple Transform (EMT) scheme is proposed. In the proposed EMT, a few sinusoidal transforms, other than DCT, have also been utilized for coding both Intra and Inter prediction residuals. The best transform, as selected from a pre-defined transform subset specified by prediction mode, is explicitly signaled in a joint coding block level manner. Moreover, to accelerate encoding process, fast methods have also been proposed by skipping unnecessary transform rate-distortion evaluations using previously encoding statistics. The proposed method has been implemented on top of High-Efficiency Video Coding (HEVC) reference software, and significant coding gain has been verified.

SHVC is the scalable extension of the latest video coding standard High Efficiency Video Coding (HEVC) and spatial resampling process is inevitable module to support spatial scalability. This paper describes in details the resampling process, including both texture and motion data resampling in SHVC, and using experimental evidence, demonstrate their benefits in terms of coding efficiency.

SHVC is the scalable extension of the latest video coding standard High Efficiency Video Coding (HEVC). Color Gamut Scalability (CGS) refers to a scalable use case in which base layer and enhancement layer have different color gamuts. In this case, special inter-layer prediction is needed to improve coding efficiency in SHVC. In this paper, a solution based on asymmetric 3D lookup table is presented for color gamut scalability. Compared to SHVC without CGS coding tool, the proposed solution provides 9.6% - 16.1% overall luma BD-rate reduction in different test cases.

Summary form only given. Screen content videos increasingly gain the popularity due to the rapid advances in cloud and multimedia technologies, which in turn requires highly efficient screen content compression. A recent standard, namely SCC is under development in JCT-VC, Joint Collaborative Team on Video Coding between ISO/IEC and ITU-T. In SCC, the most efficient new coding tool is Intra block copy (Intra BC). In this paper, we describe the Intra BC that has been proposed by the authors and adopted in the SCC standard and reference software for coding of screen content. Different from the conventional Intra prediction method where the prediction signal is derived from the spatially neighboring samples, the Intra BC mode greatly improves the prediction efficiency by fully exploiting the redundancy of repetitive patterns which typically appear in screen content. Experimental results suggest that the Intra BC mode can improve the coding efficiency significantly for typical screen content video sequences with 43.2% bit rate reduction on average.

This paper provides a technical overview of palette-based coding that was adopted into the test model for the screen content coding (SCC) extension of High Efficiency Video Coding (HEVC) standard at the 18th JCT-VC meeting. Key techniques that enable the palette mode to deliver significant coding gains for screen contents are highlighted, including palette table generation, palette table coding, and the coding methods for palette indices and escape colors. Proposed and adopted techniques up to the first version of the working draft of HEVC SCC extension and test model SCM-2.0 are presented. Experimental results are provided to evaluate the performance of the palette mode in the SCC extension of HEVC.

This paper presents an in-loop adaptive color-space transform for the HEVC Screen Content Coding extension. In the proposed method, the prediction residual is adaptively converted into a different color space to reduce the cross-component redundancy. After the ACT, the signal is coded following the existing HEVC framework. To keep the complexity as low as possible, fixed color-space transforms that are easily implemented with shift and add operations are utilized. Significant coding gains are achieved by this method in the current HEVC Screen Content Coding reference software with no increase of decoding runtime. The proposed method has been adopted to the HEVC Screen Content Coding extension.

This paper describes a scalable video codec that was submitted as a response to the joint call for proposals issued by ISO/IEC MPEG and ITU-T VCEG on HEVC scalable extension. The proposed codec uses a multi-loop decoding structure. Several inter-layer texture prediction methods are employed to remove the inter-layer redundancy. Inter-layer prediction is also used when coding enhancement layer syntax elements such as motion parameter and intra prediction mode, to further reduce bit overhead. Additionally, alternative transforms as well as adaptive coefficients scanning are used to code the prediction residues more efficiently. Experimental results are presented to demonstrate the effectiveness of the proposed scheme. When compared to HEVC single-layer coding, the additional rate overhead for the proposed scalable extension is 1.2% to 6.4% to achieve two layers of SNR and spatial scalability.

H.264/AVC uses motion compensated prediction with fractional-pixel precision to reduce temporal redundancy of the input video signal. It has been shown that the Adaptive Interpolation Filter (AIF) framework [3] can significantly improve accuracy of the motion compensated prediction. In this paper, we present the Enhanced Adaptive Interpolation Filters (E-AIF) scheme, which enhances the AIF framework with a number of useful features, aimed at both improving performance and reducing complexity. These features include the full-pixel position filter and the filter offset, the radial-shaped 12-position filter support, and a RD-based filter selection. Simulations show that E-AIF can achieve up to 20% bit rate reduction compared to H.264/AVC. Compared to all other AIF schemes, E-AIF further reduces the bit rate by up to 6%, and demonstrates the highest performance consistently.