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• Conditionally and directly skip all non-first pre-coding. • In I picture, for a CU with top-left location (x, y), if both x and y are multiples of 64, then each non-first pre-coding is skipped. • In I picture, for a CU with top-left location (x, y), if at least one of x and y is not multiples of 64 and a set of conditions is satisfied by a non-first pre-coding, then the non-first pre-coding is skipped. • In non-I picture, for CUs at any location, if a set of conditions is satisfied by a non-first pre-coding, then the non-first pre-coding is skipped. • Direct Non-First Pre-coding Skip (DNFPS) significantly reduce the coding complexity with negligible impact on coding efficiency. The third generation of Audio Video Coding Standard (AVS3) adopts sophisticated block partitioning structure with a multi-type tree, which includes Quad-Tree (QT), Binary-Tree (BT), and Extend Quad-Tree (EQT). During multi-type tree recursive block partitioning and pre-coding process of encoding, each Coding Unit (CU) of each Size at each Location (CUeSeL) of the picture is repeatedly pre-coded many times when visiting each branch of each tree. Although there are early termination mechanism, the number of visits for each CUeSeL is still very high and up to more than fifty. This process brings very high coding complexity. In order to reduce the coding complexity of AVS3, this paper proposes a method named Direct Non-First Pre-coding Skip (DNFPS) for a CUeSeL to directly and completely skip all non-first pre-coding under specific conditions. The conditions include, but are not limited to, those related to the first pre-coding. The contributions of the paper are as follows. In I pictures, for a CUeSeL with top-left location (x, y), if both x and y are multiples of 64 or if a set of conditions related to first pre-coding is satisfied, then each non-first pre-coding is skipped, and the coding result of the first pre-coding is reused for each non-first pre-coding skipped. In non-I pictures, each non-first pre-coding is skipped, and the coding result of the first pre-coding is reused for each non-first pre-coding skipped, provided a set of conditions related to first pre-coding is satisfied. The experimental results demonstrate that DNFPS has a negligible impact on coding efficiency under All Intra (AI) configurations, and coding runtime is reduced by 16 %. [ABSTRACT FROM AUTHOR]

• An adaptive HEVC video steganography algorithm is designed, which can effectively resist the PU shift-based steganalysis. • The introduction of multivariate STC allows for smaller modifications with the same embedding capacity. • The superiority of this algorithm over the state-of-the-art video steganography algorithm is verified through extensive experiments. Calibration-based steganalysis methods are a fatal threat to current HEVC steganography algorithms. The current steganography algorithms based on prediction unit (PU) still lack resistance to this type of steganalysis. The reason is that the improvements in HEVC codec provide more potential steganographic space as well as introduce more detectable distortion. Therefore, a HEVC video steganography method that has resistance to PU shift-based steganalysis is proposed in this paper. First, the PU shift phenomenon that exists in PU-based steganography is introduced. Then the existing calibration-based steganalysis method is enhanced. According to the encoding rules of HEVC, the distortion cost function according to the difference of rate distortion cost (RD cost) during recompression is designed, which aims to obtain better resistance to calibration-based steganalysis. Experimental results demonstrate that the steganography algorithm designed in this paper provides excellent resistance ability for calibration-based steganalysis. [ABSTRACT FROM AUTHOR]

Compression method for GPU streaming of discrete light fields is proposed in this paper. Views on the scene are encoded with video codec to enable streaming in real time. Instead of using a classic scheme, all frames are encoded according to one reference frame. Any frame is decoded directly, in a random-access manner that is suitable for light-field rendering methods, where only few frames are necessary on the GPU. The proposed scheme reaches the best decoding quality/time ratio in comparison to other schemes, where all preceding frames need to be decompressed, and all-key-frame video that supports random access, but is extremely large. The proposed method solves the space-requirements and streaming-bandwidth issues using the GPU accelerated decoding, and enables incorporating light-field assets in real-time 3D simulations. Compared to existing methods, the proposal is easy to implement, does not depend on specific video format or extension and is efficient on consumer GPUs. [Display omitted] • Real-time streaming method for light field rendering. • Solves light field issues such as excessive memory usage and slow streaming. • GPU-accelerated approach using nowadays actively developed HW decoders. • Ready to be used with upcoming video codecs. • Better than existing methods in speed, quality, implementation, native support. [ABSTRACT FROM AUTHOR]

In the multimedia era, exploding image and video data highlight the importance of video compression for storage and transmission. The All-Intra structure is a coding mode in HEVC and VVC, in which each frame is encoded using intra coding, and in this paper learned All-Intra coding is explored on the basis of the research of the learned image compression. A channel-wise contextual module based on channel segmentation is introduced to fully exploit non-local information. Then, two distinct attention mechanisms are designed for different feature layers to enhance the effectiveness of the transform network. Additionally, a post-processing module is employed to enhance the quality of decoded frames. Experimental results on the Kodak and Tecnick datasets demonstrate that the proposed method performs better than the majority of the recent learning-based methods and traditional image codecs (BPG, JPEG2000 and JPEG), and also perform better than traditional video codecs in terms of PSNR. • A novel video compression framework specially designed for I frame is introduced. • A channel-wise contextual module enhances context-based entropy modeling. • A post-processing module aims to enhance the quality of the reconstructed frames. • Two distinct attention mechanisms are designed for different feature layers. [ABSTRACT FROM AUTHOR]

With the developing explosion in video data delivery, perceptual video coding (PVC) plays an increasingly significant role in video compression. The just noticeable distortion (JND) reflects the tolerance limit of human visual system (HVS) to coding distortion directly, resulting in that JND-based PVC is the most important branch of video coding. This paper provides an extensive overview of JND estimation and JND-based PVC, so as to make interested readers aware of the status quo. The main contribution of this article can be briefly outlined as follows. Firstly, the general description of JND concepts and most existing computation models for JND are to be reviewed systematically. Secondly, most related works about JND-based perceptual image and video coding schemes are introduced, including JND-based coding preprocessing and JND-based codec embedding. Thirdly, in addition to a thorough summary of JND estimation and JND-based PVC, possible future directions and opportunities are analyzed and discussed. • Firstly, the general description of JND concepts and most existing computation models for JND are to be reviewed systematically. • Secondly, most related works about JND-based perceptual image or video coding schemes are introduced, including JND-based coding preprocessing and JND-based codec embedding. • Thirdly, in addition to a thorough summary of JND estimation and JND-based PVC, possible future directions and opportunities are analyzed and discussed. [ABSTRACT FROM AUTHOR]

Fast image codecs are a current need in applications that deal with large amounts of images. Graphics Processing Units (GPUs) are suitable processors to speed up most kinds of algorithms, especially when they allow fine-grain parallelism. Bitplane Coding with Parallel Coefficient processing (BPC-PaCo) is a recently proposed algorithm for the core stage of wavelet-based image codecs tailored for the highly parallel architectures of GPUs. This algorithm provides complexity scalability to allow faster execution at the expense of coding efficiency. Its main drawback is that the speedup and loss in image quality is controlled only roughly, resulting in visible distortion at low and medium rates. This paper addresses this issue by integrating techniques of visually lossless coding into BPC-PaCo. The resulting method minimizes the visual distortion introduced in the compressed file, obtaining higher-quality images to a human observer. Experimental results also indicate 12% speedups with respect to BPC-PaCo. [ABSTRACT FROM AUTHOR]