nils-herrmann/clean_scirepeval huggingface dataset:
3D video coding using advanced prediction, depth modeling, and encoder control methods

The presented approach for 3D video coding uses the multiview video plus depth format, in which a small number of video views as well as associated depth maps are coded. Based on the coded signals, additional views required for displaying the 3D video on an autostereoscopic display can be generated by depth image based rendering techniques. The developed coding scheme represents an extension of HEVC, similar to the MVC extension of H.264/AVC. However, in addition to the well-known disparity-compensated prediction advanced techniques for inter-view and inter-component prediction, the representation of depth blocks, and the encoder control for depth signals have been integrated. In comparison to simulcasting the different signals using HEVC, the proposed approach provides about 40% and 50% bit rate savings for the tested configurations with 2 and 3 views, respectively. Bit rate reductions of about 20% have been obtained in comparison to a straightforward multiview extension of HEVC without the newly developed coding tools.
Context-based adaptive binary arithmetic coding in JVT/H.26L

In this paper a new adaptive entropy coding scheme for video compression is presented. It utilizes an adaptive arithmetic coding technique to better match the first order entropy of the coded symbols and to keep track of nonstationary symbol statistics. In addition, remaining symbol redundancies are exploited by context modeling to further reduce the bit-rate. A novel approach for coding of transform coefficients and a table look-up method for probability estimation and arithmetic coding is presented. Our new approach has been integrated in the current JVT test model (JM) to demonstrate the performance gain, and it was adopted as a part of the current JVT/H.26L draft.
A highly efficient multiplication-free binary arithmetic coder and its application in video coding

A novel and highly efficient algorithm of multiplication-free binary arithmetic coding is proposed. Our proposed method relies on simple table lookups for performing the computationally critical operations of interval subdivision and probability estimation. Moreover, the underlying design principle provides a great flexibility for serving the different needs of all kind of coding applications where binary or binarized data have to be processed. A binary arithmetic coder of the type described in this paper has become part of the CABAC entropy coding scheme of the emerging H.264/AVC video coding standard. Experiments using this binary arithmetic coder in its native video coding environment demonstrate a superior coding efficiency as well as a significantly higher throughput rate in comparison to the MQ coder, which is currently being considered state-of-the-art in fast binary arithmetic coding.
A two-layered wavelet-based algorithm for efficient lossless and lossy image compression

In this paper, we propose a wavelet-based image-coding scheme allowing lossless and lossy compression, simultaneously. Our two-layered approach utilizes the best of two worlds: it uses a highly performing wavelet-based or wavelet packet-based coding technique for lossy compression in the low bit range as a first stage. For the second (optional) stage, we extend the concept of reversible integer wavelet transforms to the more flexible class of adaptive reversible integer wavelet packet transforms which are based on the generation of a whole library of bases, from which the best representation for a given residue between the reconstructed lossy compressed image and the original image is chosen using a fast-search algorithm. We present experimental results demonstrating that our compression algorithm yields a rate-distortion performance similar or superior to the best currently published pure lossy still image-coding methods. At the same time, the lossless compression performance of our two-layered scheme is comparable to that of state-of-the-art pure lossless image-coding schemes. Compared to other combined lossy/lossless coding schemes such as the emerging JPEG-2000 still image-coding standard PSNR improvements up to 3 dB are achieved for a set of standard test images.
Context-adaptive binary arithmetic coding for frame-based animated mesh compression

Context-based adaptive binary arithmetic coding (CABAC) has proven to be an efficient technique in the area of video coding. This paper presents an approach for integrating CABAC into the framework of frame-based animated mesh compression (FAMC). It presents the specific modifications and adaptations that have been worked out to adapt CABAC to the specific requirements of FAMC in order to build a solution with a higher degree of coding efficiency. For a typical test set of animated meshes, average bit rate savings of 25% have been observed for the combination of CABAC and FAMC when compared to a previous version of FAMC using a conventional N-ary arithmetic coder. The presented approach has been recently adopted as part of the MPEG-4 AFX standard.
Fast template matching for intra prediction

Intra prediction is an important step in video coding, where spatial redundancy is exploited for coding efficiency. The state-of-the-art H.265/High Efficiency Video Coding (HEVC) standard provides 35 intra prediction modes including 33 angular modes and a DC as well as a Planar mode. Although these intra prediction methods are quite efficient, there is still room for improvements, especially when complex image structures are involved. Template matching was proposed previously for H.264/Advanced Video Coding (AVC) with up to 11% BD-rate gain. However substantial decoder complexity increase from the implied search algorithm makes it less attractive for practical applications. In this paper, we propose a fast template matching intra mode for HEVC. The proposed mode is scalable in the sense of providing different trade-offs between decoder complexity and BD-rate gains. For a specific choice of parameters, fast template matching mode can achieve an average BD-rate gain of 1.15% with a maximum BD-rate gain of up to 4.6% at a 33% increase in decoder run-time. Overall, fast template matching can provide the same coding gain as conventional template matching approaches, but with significantly less decoder complexity.
Conditional motion vector refinement for improved prediction

Adapting the resolution of motion compensated prediction in a video codec is considered in this paper. A new motion search and signaling scheme for increasing the accuracy of prediction without affecting the complexity of encoding is proposed. It involves using common information available to both encoder and decoder, e.g. current slice type, texture in reference pictures, etc as a cue to control motion vector accuracy and an efficient reuse of motion information for predicting subsequent blocks. An average bit rate reduction of around 2.5% for P-pictures and 0.5% for B-pictures is observed with no extra search compared to a fixed quarter-sample resolution.
Depth Intra Coding for 3D Video Based on Geometric Primitives

This paper presents an advanced depth intra-coding approach for 3D video coding based on the High Efficiency Video Coding (HEVC) standard and the multiview video plus depth (MVD) representation. This paper is motivated by the fact that depth signals have specific characteristics that differ from those of natural signals, i.e., camera-view video. Our approach replaces conventional intra-picture coding for the depth component, targeting a consistent and efficient support of 3D video applications that utilize depth maps or polygon meshes or both, with a high depth coding efficiency in terms of minimal artifacts in rendered views and meshes with a minimal number of triangles for a given bit rate. For this purpose, we introduce intra-picture prediction modes based on geometric primitives along with a residual coding method in the spatial domain, substituting conventional intra-prediction modes and transform coding, respectively. The results show that our solution achieves the same quality of rendered or synthesized views with about the same bit rate as MVD coding with the 3D video extension of HEVC (3D-HEVC) for high-quality depth maps and with about 8% less overall bit rate as with 3D-HEVC without related depth tools. At the same time, the combination of 3D video with 3D computer graphics content is substantially simplified, as the geometry-based depth intra signals can be represented as a surface mesh with about 85% less triangles, generated directly in the decoding process as an alternative decoder output.
Extended Cross-Component Prediction in HEVC

The support for chroma formats other than 4;2;0 and bit depths higher than 10 bit has been included into the High Efficiency Video Coding (HEVC) standard by the publication of Version 2. In contrast to 4;2;2 profiles without additional dedicated coding tools relative to the Main profile, all 4;4;4 profiles specify a novel compression efficiency tool referred to as Cross-Component Prediction (CCP). This paper describes and analyses two additional extensions relative to the specified CCP variant in Version 2. In the first extension, an additional predictor is introduced, particularly, the first chroma component can also serve as the predictor for the second chroma component beside the luma component. The second extension is concerned with the binarization of the single prediction model parameter, which usually has a different distribution for R'G'B' than for Y'CbCr content. Experimental results show that the in this paper presented extensions can improve the compression efficiency by -0.7% on average for R'G'B' content, and by -1.1% for Y'CbCr content, respectively, both in terms of BD rate.
Overview of the Scalable Video Coding Extension of the H.264/AVC Standard

With the introduction of the H.264/AVC video coding standard, significant improvements have recently been demonstrated in video compression capability. The Joint Video Team of the ITU-T VCEG and the ISO/IEC MPEG has now also standardized a Scalable Video Coding (SVC) extension of the H.264/AVC standard. SVC enables the transmission and decoding of partial bit streams to provide video services with lower temporal or spatial resolutions or reduced fidelity while retaining a reconstruction quality that is high relative to the rate of the partial bit streams. Hence, SVC provides functionalities such as graceful degradation in lossy transmission environments as well as bit rate, format, and power adaptation. These functionalities provide enhancements to transmission and storage applications. SVC has achieved significant improvements in coding efficiency with an increased degree of supported scalability relative to the scalable profiles of prior video coding standards. This paper provides an overview of the basic concepts for extending H.264/AVC towards SVC. Moreover, the basic tools for providing temporal, spatial, and quality scalability are described in detail and experimentally analyzed regarding their efficiency and complexity.
Video Compression Using Nested Quadtree Structures, Leaf Merging, and Improved Techniques for Motion Representation and Entropy Coding

A video coding architecture is described that is based on nested and pre-configurable quadtree structures for flexible and signal-adaptive picture partitioning. The primary goal of this partitioning concept is to provide a high degree of adaptability for both temporal and spatial prediction as well as for the purpose of space-frequency representation of prediction residuals. At the same time, a leaf merging mechanism is included in order to prevent excessive partitioning of a picture into prediction blocks and to reduce the amount of bits for signaling the prediction signal. For fractional-sample motion-compensated prediction, a fixed-point implementation of the maximal-order minimum-support algorithm is presented that uses a combination of infinite impulse response and FIR filtering. Entropy coding utilizes the concept of probability interval partitioning entropy codes that offers new ways for parallelization and enhanced throughput. The presented video coding scheme was submitted to a joint call for proposals of ITU-T Visual Coding Experts Group and ISO/IEC Moving Picture Experts Group and was ranked among the five best performing proposals, both in terms of subjective and objective quality.
Constrained inter-layer prediction for single-loop decoding in spatial scalability

The scalability extension of H.264/AVC uses an oversampled pyramid representation for spatial scalability, where for each spatial resolution a separate motion compensation or MCTF loop is deployed. When the reconstructed signal at a lower resolution is used to predict the next higher resolution, the motion compensation or MCTF loops including the deblocking filter operations of both resolutions have to be executed. This imposes a large complexity burden on the decoding of the higher resolution signals, especially when multiple spatial layers are utilized. In this paper, we investigate the approach to only allow prediction between spatial layers for parts of the lower resolution pictures that are intra-coded in order to avoid decoding that requires multiple motion compensation or MCTF loops. Experimental results evaluate the effectiveness of the proposed approach.
HEVC performance and complexity for 4K video

The recently finalized High-Efficiency Video Coding (HEVC) standard was jointly developed by the ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC Moving Picture Experts Group (MPEG) to improve the compression performance of current video coding standards by 50%. Especially when it comes to transmit high resolution video like 4K over the internet or in broadcast, the 50% bitrate reduction is essential. This paper shows that real-time decoding of 4K video with a frame-level parallel decoding approach using four desktop CPU cores is feasible.
Extension of High Efficiency Video Coding (HEVC) for multiview video and depth data

This paper presents an approach for 3D video coding that uses a format in which a small number of views as well as associated depth maps are coded and transmitted. At the receiver side, additional views required for displaying the 3D video on an autostereoscopic display can be generated based on the corresponding decoded signals by using depth image based rendering (DIBR) techniques. In terms of coding technology, the proposed coding scheme represents an extension of High Efficiency Video Coding (HEVC), similar to the Multiview Coding (MVC) extension of H.264/AVC. Besides the well-known disparity-compensated prediction, advanced techniques for inter-view and inter-component prediction, the representation of depth blocks, and the encoder control for depth signals have been developed and integrated. In comparison to simulcasting the different signals using HEVC, the proposed approach provides about 40% and 50% average bit rate savings for a whole test set when configured to comply with a 2- and 3-view scenario, respectively. The proposed codec was submitted as response to a Call for Proposals on 3D Video Technology issued by the ISO/IEC Moving Picture Experts Group (MPEG) and it was ranked as the overall best performing HEVC-based proposal in the related subjective tests.
Global and local rate-distortion optimization for Lapped Biorthogonal Transform coding

It is a well-known fact that, in order to overcome annoying blocking artifacts, transforms with block-overlapping basis functions have been proposed for image coding. Typically in transform coding, the encoder determines the transform coefficient values by applying the forward transform followed by scalar quantization. In this paper we present an approach, how rate-distortion optimized Lapped Biorthogonal Transform (LBT) coefficient values can be determined by solving ℓ1-regularized least squares problems. We compare a global version, where all the transform coefficients are obtained in one single optimization step, and a local version, where the optimization is done separately for each block, which results in losing optimality, but achieving highly reduced complexity. Our simulation results show gains of about 0.5 dB PSNR compared to ordinary forward transform and scalar quantization with only small losses (< 0.1 dB) for the local variant.
Block Merging for Quadtree-Based Partitioning in HEVC

The joint development of the upcoming High Efficiency Video Coding (HEVC) standard by ITU-T Video Coding Experts Group and ISO/IEC Moving Picture Experts Group marks a new step in video compression capability. In technical terms, HEVC is a hybrid video-coding approach using quadtree-based block partitioning together with motion-compensated prediction. Even though a high degree of adaptability is achieved by quadtree-based block partitioning, this approach has certain intrinsic drawbacks, which may result in redundant sets of motion parameters being transmitted. Previous work has shown that those redundancies can effectively be removed by merging the leafs of a particular quadtree structure. Following this concept, a block merging algorithm for HEVC is now proposed. This algorithm generates a single motion parameter set for a whole region of contiguous motion-compensated blocks. In this paper, we describe the various components of the proposed block merging algorithm and, using experimental evidence, demonstrate their benefits in terms of coding efficiency.
Adaptive cross-component prediction for 4:4:4 high efficiency video coding

The work on support for higher bit depths and 4:2:2 as well as 4:4:4 chroma sampling formats for the High Efficiency Video Coding (HEVC) standard is currently being conducted under the term Range Extensions (RExt). A technique that exploits the correlation between residual color components in 4:4:4 chroma sampling format, also referred to as Cross-Component Prediction (CCP), has been adopted as part of the current RExt draft. In this paper, this relatively simple but yet effective CCP scheme is presented. Conceptually, CCP relies on the idea that an adaptively switched predictor based on a linear model is invoked for coding of the residuals of the second and third color component by using the residual of the first color component. Experimental results show that, depending on the underlying color space, average bit-rate savings in the range of 2-18% or 3-26% can be achieved by CCP for test sets of natural and screen content, respectively.
Progressive texture video coding

We present a novel video coding approach which provides the functionality of fine granular bitstream scalability. The proposed progressive texture video coding (PTVC) scheme consists of two parts: the current ITU-T H.26L test model for coding macroblock mode and motion information only; a new technique for progressively coding all intra and inter texture information thus providing an embedded bitstream. It can still be decoded with moderate quality degradation in case of partial loss of the bitstream. It is therefore well suited for multicast or broadcast scenarios where time varying or different fixed bitrates are provided to the clients, as no transcoding or multiple coding process is required.
Overview of the Scalable H.264/MPEG4-AVC Extension

The scalable extension of H.264/MPEG4-AVC is a current standardization project of the joint video team of the ITU-T Video Coding Experts Group and the ISO/IEC moving picture experts group. This paper gives an overview of the design of the scalable H.264/MPEG4-AVC extension and describes the basic concepts for supporting temporal, spatial, and SNR scalability. The efficiency of the described concepts for providing spatial and SNR scalability is analyzed by means of simulation results and compared to H.264/MPEG4-AVC compliant single layer coding.
Very low bit-rate video coding using wavelet-based techniques

In this paper, we propose a very low bit-rate video coding scheme based on a discrete wavelet transform (DWT), block-matching motion estimation (BME), and overlapped block motion compensation (OBMC). Our approach reveals that the coding process works more efficiently if the quantized wavelet coefficients are preprocessed by a mechanism exploiting the redundancies in the wavelet subband structure. Thus, we introduce a new framework of preceding techniques based on the concepts of partitioning, aggregation, and conditional coding (PACC). Our experimental results show that our PACC coder outperforms the VM (Version 5.1) of MPEG4 both for the coding of intraframes (1-2 dB PSNR) and residual frames (up to 1.5 dB PSNR) of typical MPEG4 test sequences. The subjective quality of reconstructed video is, in general, superior to that obtained from the VM implementation. In addition, when restricted to the intraframe mode, the proposed coding algorithm produces results which are among the best reported for still image compression.
Rate-distortion optimised quantisation for HEVC using spatial just noticeable distortion

Due to the higher requirements associated with Ultra High Definition (UHD) resolutions in terms of memory and transmission bandwidth, the feasibility of UHD video communication applications is strongly dependent on the performance of video compression solutions. Even though the High Efficiency Video Coding (HEVC) standard allows significantly superior rate-distortion performances compared to previous video coding standards, further performance improvements are possible when exploiting the perceptual properties of the Human Visual System (HVS). This paper proposes a novel perceptual-based solution fully compliant with the HEVC standard, where a low complexity Just Noticeable Distortion model is used to drive the encoder's rate-distortion optimised quantisation process. This technique allows a simple and effective way to influence the decisions made at the encoder, based on the limitations of the HVS. The experiments conducted for UHD resolutions show average bitrate savings of 21% with no visual quality degradations when compared to the HEVC reference software.
Video coding with H.264/AVC: tools, performance, and complexity

H.264/AVC, the result of the collaboration between the ISO/IEC Moving Picture Experts Group and the ITU-T Video Coding Experts Group, is the latest standard for video coding. The goals of this standardization effort were enhanced compression efficiency, network friendly video representation for interactive (video telephony) and non-interactive applications (broadcast, streaming, storage, video on demand). H.264/AVC provides gains in compression efficiency of up to 50% over a wide range of bit rates and video resolutions compared to previous standards. Compared to previous standards, the decoder complexity is about four times that of MPEG-2 and two times that of MPEG-4 Visual Simple Profile. This paper provides an overview of the new tools, features and complexity of H.264/AVC.
Increasing data throughput in PIPE coding using extended v2v-codes

Entropy coding schemes like context-based adaptive binary arithmetic coding (CABAC) as used in the H.264/AVC video coding standard are established in the market. To increase throughput and possibilities for parallelization, probability interval partitioning entropy coding (PIPE) was developed. It replaces the arithmetic entropy coding step of the CABAC scheme with a set of bin coders, each operating at a fixed probability. In this paper, the use of variable-to-variable length (v2v) codes for the bin coders is discussed and a concept for increasing the throughput of table-based v2v-coder implementations is developed. It is based on code word concatenation and thus virtually neutral in terms of coding efficiency. Using this technique in the emerging HEVC video coding standard show an overall decoding time reduction of up to 5% when compared to the unchanged CABAC.