nils-herrmann/clean_scirepeval huggingface dataset:
Predictive coding of intra prediction modes for high efficiency video coding

The High Efficiency Video Coding (HEVC) standardization process currently underway includes many tools for the coding of intra pictures. HEVC allows for many more intra prediction modes or directions as compared to previous standards. Efficient coding of these modes is therefore important because the modes consume a non-negligible portion of the total bit-stream used for coding intra pictures. In this paper, a predictive coding method is proposed to reduce the number of bits needed for signaling the intra prediction modes, where the spatial angular correlation between the intra prediction mode of the current Prediction Unit (PU) and the neighboring PUs is computed using a few modulo-N arithmetic operations that do not impact encoder or decoder run-times. The proposed method provides similar or greater improvements in compression efficiency as compared to competing tools, while requiring no changes to the existing bit-stream syntax.
View Synthesis Prediction for Rate-Overhead Reduction in FTV

This paper proposes the use of view synthesis prediction for reducing rate-overhead incurred by transmitting depth-maps in free viewpoint TV applications. In particular, the scenario in which depth-maps with varying-degrees of quality is available at the decoder for free viewpoint video applications is considered. The depth-map for each view is encoded separately from the multiview video and used to generate intermediate views as well as view synthesis prediction for coding efficiency improvement. It is shown that the rate overhead incurred by coding high-quality depth maps can be offset by reducing the necessary bitrate for coding multiview (texture) video with the proposed technique. The effect of down-sampling as well as the use of different QPs for the depth map are also discussed.
Wyner-Ziv coding of multispectral images for space and airborne platforms

This paper investigates the application of lossy distributed source coding to high resolution multispectral images. The choice of distributed source coding is motivated by the need for very low encoding complexity on space and airborne platforms. The data consists of red, blue, green and infra-red channels and is compressed in an asymmetric Wyner-Ziv setting. One image channel is compressed using traditional JPEG and transmitted to the ground station where it is available as side information for Wyner-Ziv coding of the other channels. Encoding is accomplished by quantizing the image data, applying a Low-Density Parity Check code to the remaining three image channels, and transmitting the resulting syndromes. At the ground station, the image data is recovered from the syndromes by exploiting the correlation in the frequency spectrum of the band being decoded and the JPEG-decoded side information band. In experiments with real uncompressed images obtained by a satellite, the rate-distortion performance is found to be vastly superior to JPEG compression of individual image channels and rivals that of JPEG2000 at much lower encoding complexity.
Successive packing based interleaver design for turbo codes

The interleaver is the key component in both turbo encoder and decoder. It has been shown that good turbo code performance can be obtained by using a pseudo-random interleaver. However, it is difficult to analyze the corresponding pseudo-random algorithms such that the performance can be guaranteed, and furthermore they are computationally expensive. We focus on a deterministic turbo code interleaver design. A novel successive packing (SP) based turbo code interleaver design method is proposed. In this method, the interleaver is generated based on iterative packing of the basis interleaver. We have shown that SP based interleavers possess the following desirable features: prunability; adaptability to various criteria; pseudo-random distribution. Simulation results demonstrate the superior performance of SP over other deterministic interleaver design techniques.
Motion Mapping for MPEG-2 to H.264/AVC Transcoding

This paper describes novel motion mapping algorithms aimed for low-complexity MPEG-2 to AVC transcoding. The proposed algorithms efficiently map incoming MPEG-2 motion vectors to outgoing AVC motion vectors regardless of the block sizes that the motion vectors correspond to. Extensive simulation results show that our proposed transcoder incorporating the proposed algorithms achieves very good rate-distortion performance with low complexity. Compared with the cascaded decoder-encoder solution, the proposed approach could achieve similar coding efficiency while significantly reduce the complexity.
Extensions of H.264/AVC for Multiview Video Compression

We consider multiview video compression: the problem of jointly compressing multiple views of a scene recorded by different cameras. To take advantage of the correlation between views, we propose using disparity compensated view prediction and view synthesis and describe how these features can be implemented by extending the H.264/AVC compression standard. Finally, we discuss experimental results on the test sequences from the MPEG call for proposals on multiview video.
TV architecture supporting multiple 3D services

This paper describes changes to the television architecture to support 3D video, with emphasis on the receiver and display processor. It is expected that multiple 3D services will be available in the near future. While the current 3D-Ready televisions are able to display uncompressed stereoscopic video signals, the capabilities are limited and need to be expanded. To enable more diverse sources of content, the television will also need to handle compressed stereoscopic formats from various delivery channels. Components of the television architecture that are impacted by new content sources are discussed, and standardization efforts that aim to achieve interoperability with the television receiver and display functionalities are also highlighted.
Fast region-of-interest transcoding for JPEG 2000 images

The paper presents a newly developed region-of-interest (ROI) transcoding method for JPEG 2000 images; it can be used for many progressive image/video streaming applications. The proposed method takes advantage of the empty packet property provided by the JPEG 2000 standard to elevate the priority of the ROI. Based on the user specified ROI information and progressive parameters, the developed transcoder extracts the selected ROI and background packets at the desired quality and suppresses the unselected packets to a low quality. Since the transcoder only performs a reorganization of the packets in the original coded bitstream, it does not involve any re-encoding operation. Compared to other ROI coding schemes in the literature, the proposed method has the advantages of lower complexity and faster processing. Therefore, it is very suitable for real-time applications.
Overview of the Multiview and 3D Extensions of High Efficiency Video Coding

The High Efficiency Video Coding (HEVC) standard has recently been extended to support efficient representation of multiview video and depth-based 3D video formats. The multiview extension, MV-HEVC, allows efficient coding of multiple camera views and associated auxiliary pictures, and can be implemented by reusing single-layer decoders without changing the block-level processing modules since block-level syntax and decoding processes remain unchanged. Bit rate savings compared with HEVC simulcast are achieved by enabling the use of inter-view references in motion-compensated prediction. The more advanced 3D video extension, 3D-HEVC, targets a coded representation consisting of multiple views and associated depth maps, as required for generating additional intermediate views in advanced 3D displays. Additional bit rate reduction compared with MV-HEVC is achieved by specifying new block-level video coding tools, which explicitly exploit statistical dependencies between video texture and depth and specifically adapt to the properties of depth maps. The technical concepts and features of both extensions are presented in this paper.
Minimum drift architectures for 3-layer scalable DTV decoding

This paper describes new techniques for implementing a low-cost video decoder that can decode an HDTV bitstream and display the signal at lower resolutions. Two key algorithms are discussed: downconversion and low-resolution motion compensation. In the proposed scheme, incoming blocks are subject to a down-conversion process within the decoding loop, hence motion compensation is performed from the downconverted images. The filters used for down-conversion are based on the concept of frequency synthesis, and the filters used to perform the low-resolution motion compensation are determined by an optimal least squares solution. Using these algorithms, three different architectures that provide equal quality with varying system level complexity are presented; the first is directly derived from the initial model of the low-resolution decoder, another attempts to reduce the amount of computation for the IDCT, while another addresses the concerns regarding the amount of interface with an existing decoder structure. All of the above systems are hierarchical with regard to the logic used for filtering and scalable in the amount of memory which is required to reconstruct each output layer. Our simulation results demonstrate that high quality video can be provided at lower-resolutions with significant memory savings.
New techniques for next generation video coding

Video coding standards are rapidly evolving with the advance of the video compression techniques. As the state of the art video coding standard, H.264/AVC exhibits superior coding performance improvement over its predecessors. Currently, both VCEG and MPEG are launching their next-generation video coding project, which aims to meet the new requirements future applications may impose on the video coding standard. In this paper, we summarize the progress of those next generation video coding standard projects and existing new video coding techniques. Moreover, we also present details on our implementation of second-order prediction and reduced resolution update, followed by some experimental results.
RD-Optimized View Synthesis Prediction for Multiview Video Coding

We propose a rate-distortion optimized framework that incorporates view synthesis for improved prediction in multiview video coding. In the proposed scheme, block-based depth and correction vectors are encoded and used at the decoder to generate the view synthesis prediction data. The proposed method employs variable block-size depth/motion search, optimal mode decision including view synthesis prediction, and CABAC encoding of depth and correction vectors. A sub-pixel reference matching technique is also introduced to improve prediction accuracy of the view synthesis prediction. Novel variants of the skip and direct modes are presented, which infer the depth and correction vector information from neighboring blocks in a synthesized reference picture to reduce the bits needed for the view synthesis prediction mode. Experimental results demonstrate improved coding efficiency with the proposed techniques.
Video transcoding architectures and techniques: an overview

Throughout this article, we concentrate on the transcoding of block-based video coding schemes that use hybrid discrete cosine transform (DCT) and motion compensation (MC). In such schemes, the frames of the video sequence are divided into macroblocks (MBs), where each MB typically consists of a luminance block (e.g., of size 16 /spl times/ 16, or alternatively, four 8 /spl times/ 8 blocks) along with corresponding chrominance blocks (e.g., 8 /spl times/ 8 Cb and 8 /spl times/ 8 Cr). This article emphasizes the processing that is done on the luminance components of the video. In general, the chrominance components can be handled similarly and will not be discussed in this article. We first provide an overview of the techniques used for bit-rate reduction and the corresponding architectures that have been proposed. Then, we describe the advances regarding spatial and temporal resolution reduction techniques and architectures. Additionally, an overview of error resilient transcoding is also provided, as well as a discussion of scalable coding techniques and how they relate to video transcoding. Finally, the article ends with concluding remarks, including pointers to other works on video transcoding that have not been covered in this article, as well as some future directions.
Resampling, Antialiasing, and Compression in Multiview 3-D Displays

Multiview three-dimensional (3-D) displays offer viewing of high-resolution stereoscopic images from arbitrary positions without glasses. This article surveyed different approaches to develop signal processing algorithms for these displays. Such displays consist of view-dependent pixels that reveal a different color according to the viewing angle. Therefore, the left and right eye of an observer sees slightly different images on the screen. This leads to the perception of 3-D depth and parallax effects when the observer moves. Although the basic optical principles of multiview auto-stereoscopy have been known for over a century, only recently displays with increased resolution, or systems based on multiple projectors, have made this approach practical.
Next-Generation 3D Formats with Depth Map Support

This article reviews the most recent extensions to the Advanced Video Coding (AVC) and High Efficiency Video Coding (HEVC) coding standards, which integrate depth video to support advanced multiview and 3D video functionalities. All the extensions provide single-view compatibility, while some extensions add depth support on top of conforming stereoscopic bitstreams. To achieve the highest gains in coding efficiency, depth information is utilized in coding the texture views. The compression formats described in this article can be used to support emerging auto-stereoscopic displays and free-viewpoint video functionalities.
Rate-distortion optimized bit allocation for error resilient video transcoding

A key issue in video transcoding for transmission in an error-prone environment is to balance the rate used for the video source with bits allocated for error resilience such that the end-to-end distortion is minimized under the given rate constraint and channel condition. The approach presented in this paper differs from previous works by accounting for the inter-frame dependence in both video source requantization and error propagation of motion compensated video. Based on the rate-distortion models developed in this paper, an optimal group-of-picture based bit allocation scheme is proposed. We also propose a sub-optimal scheme that is suitable for a real-time implementation. Both the optimal and sub-optimal scheme achieves better PSNR performances than the fixed heuristic bit allocation scheme.
Overview of the Stereo and Multiview Video Coding Extensions of the H.264/MPEG-4 AVC Standard

Significant improvements in video compression capability have been demonstrated with the introduction of the H.264/MPEG-4 advanced video coding (AVC) standard. Since developing this standard, the Joint Video Team of the ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC Moving Picture Experts Group (MPEG) has also standardized an extension of that technology that is referred to as multiview video coding (MVC). MVC provides a compact representation for multiple views of a video scene, such as multiple synchronized video cameras. Stereo-paired video for 3-D viewing is an important special case of MVC. The standard enables inter-view prediction to improve compression capability, as well as supporting ordinary temporal and spatial prediction. It also supports backward compatibility with existing legacy systems by structuring the MVC bitstream to include a compatible “base view.” Each other view is encoded at the same picture resolution as the base view. In recognition of its high-quality encoding capability and support for backward compatibility, the stereo high profile of the MVC extension was selected by the Blu-Ray Disc Association as the coding format for 3-D video with high-definition resolution. This paper provides an overview of the algorithmic design used for extending H.264/MPEG-4 AVC towards MVC. The basic approach of MVC for enabling inter-view prediction and view scalability in the context of H.264/MPEG-4 AVC is reviewed. Related supplemental enhancement information (SEI) metadata is also described. Various “frame compatible” approaches for support of stereo-view video as an alternative to MVC are also discussed. A summary of the coding performance achieved by MVC for both stereo- and multiview video is also provided. Future directions and challenges related to 3-D video are also briefly discussed.
Error resilient methods for real-time MPEG-4 video streaming

Two error resilient approaches are proposed respectively, to replenish intra and inter frame in this work. First we propose a spatial-domain error concealment method to conceal corrupted still images and intra-coded (I) frames. It can recursively restore pixels from the previously concealed pixels, which are selected by a proposed evaluation method. In such method, object edges can be replenished with a low complexity. Second, we propose an error resilient approach for P-frame. With our proposed approach, only a small amount of side information is extracted and packed at the end of every frame. Decoder can easily restore motion vector from the side information for concealment. Experimental results show that the proposed algorithm can provide better visual quality in comparison with the existing approaches.
Media conversions to support mobile users

The purpose of this paper is to provide an overview of the signal processing techniques that will allow mobile users to enjoy a wide range of multimedia services. In the near future, mobile terminals will be equipped with the capability to decode and playback a variety of audio-visual formats. With the increase in number of formats and the presence of various network, terminal and user constraints, media conversion is expected to play a key role in the delivery of content to mobile users. This paper reviews some of the basic technology required for media conversion and provides some discussion about the types of services that could be supported.
Object-based coding for long-term archive of surveillance video

This paper describes video coding and segmentation techniques that can be used to achieve significant increase in storage capacity. Specifically, we examine the possibility to use object- based coding for efficient long-term archiving of surveillance video. We consider surveillance systems with many camera sources in which we are required to store several months of video data for each source, thus storage capacity is a major concern. The paper considers several automatic segmentation algorithms. With each algorithm, we analyze the shape coding overhead and implication on overall storage requirements, as well as the effect each algorithm has on the reconstructed quality of frames. Additionally, this paper reviews techniques to dynamically control the temporal rate of objects in the scene and perform bit allocation. Experimental results show that up to 90% savings in storage can be achieved with the proposed method compared to frame-based video coding techniques. The cost for this savings is that the accuracy of the background is compromised; however, we feel that this is satisfactory for the application under consideration.
An overview of MPEG-4 object-based encoding algorithms

Describes several object-based encoding issues and provides solutions based on the MPEG-4 coding standard. Specifically, we first consider the general problem of object-based rate control and the allocation of bits among each object. Going a step further, we then discuss the issues related to the allocation of bits between shape and texture, and propose a method to model the rate distortion characteristics of the shape. Finally, we describe some preliminary work that we have been doing towards optimizing the tradeoff in spatial and temporal quality. For object-based coding, it is believed that significant coding gains can be achieved.
Depth Reconstruction Filter and Down/Up Sampling for Depth Coding in 3-D Video

A depth image represents three-dimensional (3-D) scene information and is commonly used for depth image-based rendering (DIBR) to support 3-D video and free-viewpoint video applications. The virtual view is generally rendered by the DIBR technique and its quality depends highly on the quality of depth image. Thus, efficient depth coding is crucial to realize the 3-D video system. In this letter, we propose a depth reconstruction filter and depth down/up sampling techniques to improve depth coding performance. Experimental results demonstrate that the proposed methods reduce the bit-rate for depth coding and achieve better rendering quality.
Feature extraction for a Slepian-Wolf biometric system using LDPC codes

We present an information-theoretically secure biometric storage system using graph-based error correcting codes in a Slepian-Wolf coding framework. Our architecture is motivated by the noisy nature of personal biometrics and the requirement to provide security without storing the true biometric at the device. The principal difficulty is that real biometric signals, such as fingerprints, do not obey the i.i.d. or ergodic statistics that are required for the underlying typicality properties in the Slepian-Wolf coding framework. To meet this challenge, we propose to transform the biometric data into binary feature vectors that are i.i.d. ), independent across different users, and related within the same user through a BSC-p channel with small p< 0.5. Since this is a standard channel model for LDPC codes, the feature vectors are now suitable for LDPC syndrome coding. The syndromes serve as secure biometrics for access control. Experiments on a fingerprint database demonstrate that the system is information-theoretically secure, and achieves very low false accept rates and low false reject rates.
Distributed compression of zerotrees of wavelet coefficients

A distributed coding algorithm is presented for compression of wavelet-transformed data. Data structures based on zerotrees are exploited for efficient compression of the significance map of wavelet coefficients. The coefficients are scanned in two stages, with a significance pass and refinement pass, similar to the SPIHT algorithm. The bits resulting from these passes are Slepian-Wolf coded using an LDPC syndrome code selected from a bank of available codes. A key realization is that, for each bitplane of the wavelet coefficients, the significance pass of the source data can be synchronized with that of the side information. This allows distributed compression of the significance pass. This is substantially different from previous mixed approaches in which the refinement pass was Slepian-Wolf coded, but the significance pass was coded independently. Rate-distortion results are presented for images from the ALOS AVNIR-2 multispectral dataset and compared against those obtained with SPIHT and JPEG2000.
Frequency domain down-conversion of HDTV using adaptive motion compensation

The paper investigates the possible means of down converting an incoming HDTV signal into one which is suitable for display onto an NTSC monitor. We present a novel frequency synthesis algorithm which constructs a set of 8/spl times/8 DCT coefficients from four original 8/spl times/8 DCT blocks. Also, a down-conversion decoder employing a unique adaptive motion compensation algorithm is presented. Using this fixed motion compensation algorithm, the proposed down-conversion technique is compared to the conventional method. Both yield acceptable image sequences with different trade-offs in complexity and quality.