nils-herrmann/clean_scirepeval huggingface dataset:
Robust Streaming of Offline Coded H.264/AVC Video Via Alternative Macroblock Coding

An error resilient video streaming scheme that transmits offline coded H.264/AVC video through erroneous channels, called the alternative macroblock coding (AMC) scheme, is proposed in this work. In the AMC scheme, each macroblock can be reconstructed from one default and several alternative versions coded using different predictions. During the transmission, the sender tracks ACK or NACK messages from the receiver to detect transmission errors. When the reference used in the default version of a macroblock that has not been transmitted is corrupted by errors, one of its alternative versions that has the correctly received reference is selected to replace the default version in the output bit stream to stop error propagation. The AMC scheme is designed to ensure that the bit stream replacement during streaming will not cause significant mismatch at the decoder end and neither introduce large bit rate overhead to the transmitted bit stream. Furthermore, adaptive quantization selection and bit stream replacement methods are developed to improve the rate-distortion performance of received video. It is demonstrated by experimental results that the AMC scheme is effective in reducing error propagation in offline coded H.264/AVC video.
On-line Music Beat Tracking with Kalman Filtering and Probability Data Association (KF-PDA)

An on-line music beat tracking algorithm with Kalman filtering (KF) and probability data association (PDA) is proposed. The KF-PDA method not only estimates the music tempo and beat pulse positions in real-time but also provides a temporal metrical unit for human-perception-like processing. The superior performance of the proposed KF-PDA beat tracking system is demonstrated using the MIREX beat tracking competition's practice data set.
Design of wavelet-based image codec in memory-constrained environment

This work presents a high-performance wavelet transform based image coder that is designed for image compression in a system with limited resources. In this image coder, the dual-sliding wavelet transform (DSWT) is first applied to the image data to generate wavelet coefficients in fixed-size blocks. Here, a block consists of wavelet coefficients only from a single subband. Then, the resulting coefficient blocks are directly coded with the low-complexity binary description (LCBiD) coefficient coding algorithm. No parent-child relationship is exploited in the coding process. There is no intermediate buffering needed between DSWT and LCBiD. The compressed bit stream generated by the proposed coder is both SNR and resolution scalable, as well as highly resilient to transmission errors. Both DSWT and LCBiD process the data in blocks whose size is independent of the size of the input image. This gives more flexibility in its implementation. The codec has a very good coding performance even the size of a coefficient block is as small as (16,16).
Analysis of multi-hypothesis motion compensated prediction for robust video transmission

The relationship between the error propagation effect and the hypothesis number of a multi-hypothesis motion compensated prediction (MHMCP) coder is analyzed in this work. MHMCP enhances the error resilient property of compressed video but demands a higher bit rate for the coding of motion information. We study the rate-distortion performance of MHMCP in an error prone environment, and then perform extensive experiments to confirm analytical results. Several design guidelines for the MHMCP coder are drawn based on the analytical and experimental results.
Musical Onset Detection with Joint Phase and Energy Features

A new approach to musical onset detection by detecting the significant change of joint energy and phase features is proposed in this work. We modify the phase deviation method in (Duxbury et al., 2003) to yield a more robust phase feature. To capture the energy deviation of an audio waveform along time, we compute the error of a forward linear prediction filter as the energy feature. Several ways to fuse obtained energy and phase features are discussed and compared. It is demonstrated by experimental results that a proper scheme to integrate energy and phase features can provide excellent onset detection results.
Power control, adaptive modulation and subchannel allocation for multiuser downlink OFDM

A scheme to control transmission power, allocate subcarriers, and choose modulation schemes for each mobile terminal (MT) in a multiuser downlink OFDM system is investigated in this work. This proposed scheme attempts to make OFDM systems more flexible and robust to channel variations. The problem is decomposed into two stages. In the first stage, the min-max criterion is used to control the transmission power among different MTs in different allocated subchannels. Then, in the second stage, we choose modulation schemes for allocated subchannels of each MT with an objective to maximize the total transmission rate while satisfying the performance requirement of each MT. Simulations are conducted to demonstrate the performance of the proposed scheme under a varying number of MTs and a range of symbol error rates (SERs).
Opportunistic Access with Random Subchannel Backoff (OARSB) for OFDMA Uplink

A distributed medium access control (MAC) algorithm for uplink OFDMA networks under the IEEE 802.16 framework is proposed and analyzed in this work. We present a simple yet efficient algorithm to enhance the system throughput by integrating opportunistic medium access and collision resolution through random subchannel backoff. Consequently, the resulting algorithm is called the opportunistic access with random subchannel backoff (OARSB) scheme. OARSB not only achieves distributed coordination among users but also reduces the amount of information exchange between the base station and users. The throughput and delay performance analysis of OARSB is conducted using a Markov chain model. The superior performance of OARSB over an existing scheme is demonstrated by analysis as well as computer simulation.
Adaptive resource allocation for multimedia QoS management in wireless networks

Adaptive resource allocation for multimedia quality of service (QoS) support in broadband wireless networks is examined in this work. A service model consisting of three service classes with different handoff-dropping requirements is presented. Appropriate call-admission control and resource-reservation schemes are developed to allocate resources adaptively to the real-time service classes with a stringent delay bound. Moreover, we propose an effective and efficient measurement-based dynamic resource allocation scheme to meet the target handoff-dropping probability. The nonreal-time applications, serviced by the best-effort model, are supported. The system accommodates adaptive multimedia applications to further reduce the blocking and dropping probabilities of real-time applications. Based on a multidimensional model analysis, simulations are conducted to evaluate the system performance. The simulation results show that the proposed system can satisfy the desired QoS of multimedia applications under different traffic loads, while achieving high utilization.
Demo of wireless multimedia transmission in mobile environments

Laptop PCs equipped with a cellular phone is a new generation of wireless communication device for multimedia data transmission. In this work, we investigate the transmission of encoded multimedia data via the wireless link of the above system. The bandwidth of the wireless channel is much narrower and the noise level is higher in comparison with the wired network. We implement an error control scheme for multimedia data transmission, including audio, video, digital maps and animated graphics. The animated graphics is coded with a new 2-D mesh coding algorithm that is effective in coding efficiency and error resiliency. An implementation of such a wireless communication system is demonstrated.
Relative priority based QoS interaction between video applications and differentiated service networks

In this research, we investigate quality of service (QoS) interaction provisioning between video applications and components of the DiffServ network. QoS interaction is performed through the mapping of video packets based on the relative quality index (RQI), which represents the relative preference in terms of loss and delay, onto the adaptive packet forwarding mechanism in a DiffServ network. To verify the efficiency of the proposed strategy, the end-to-end performance is evaluated through error resilient packet video transmission over a simulated DiffServ network. Results show that the proposed QoS interaction framework results in an enhanced end-to-end video quality at the same cost constraint.
Screen content coding for HEVC using edge modes

In this work, a new coding tool called Edge Mode is proposed for HEVC intra coding, aimed at improving coding efficiency for screen content video. A set of edge modes that correspond to edge positions are identified based upon intra prediction directions. Then, a simplified scheme is developed to select the best edge mode. To avoid applying a transform over strong edges, directional 2D separable transforms are applied to blocks partitioned using these edge modes. Experimental results show that HEVC with edge modes (HEVC/EM) can achieve up to an 18% reduction in bit-rate as compared to unmodified HEVC, with an average reduction of 10.4% for screen content video sequences.
Dynamic call admission control and resource reservation with interference guard margin (IGM) for CDMA systems

A dynamic call admission control and resource reservation scheme suitable for CDMA systems is proposed. Preferential treatment is given to high priority calls by preserving an interference guard margin (IGM), which is dynamically adjusted by referencing traffic conditions in neighboring cells based upon users' quality of service. A comprehensive service model is used including users' service rates, priority levels, mobility and rate adaptivity. Simulations are conducted by OPNET to study the performance in terms of the objective function under different traffic conditions.
Progressive image indexing and retrieval based on embedded wavelet coding

A complete wavelet-based image storage and indexing system is proposed in this research. The proposed indexing features take account of the color, brightness, texture, frequency, and spatial information of a given query image. All features can be naturally extracted as a byproduct during the image compression. Since coding and indexing are integrated in an unified framework in the proposed system, the database management is greatly simplified. Extensive experimental results are given to demonstrate the retrieval performance of the new approach.
Wireless Multi-party video conferencing with network coding

In this paper, we propose a cost-effective scheme for robust wireless multi-party video conferencing based on network coding (NC). The main idea is the adoption of a NC scheme to enhance robust transmission, to simplify the erasure protection procedure, and to reduce the downlink bandwidth by leveraging the properties of opportunistic NC and wireless broadcasting. We design a pipelining schedule to meet the delay requirement for real-time video conferencing. The proposed NC method outperforms the opportunistic network coding method by a significant margin and reduces the downlink bandwidth of the overall video bit rate.
Robust MC-CDMA-Based Fingerprinting Against Time-Varying Collusion Attacks

The design of robust fingerprinting systems for traitor tracing against time-varying collusion attacks in protecting continuous media, such as audio and video, is investigated in this research. We first show that it can be formulated as a multiuser detection problem in a wireless communication system with a time-varying channel response. Being inspired by the multicarrier code-division multiaccess technique, we propose a fingerprinting system that consists of three modules: 1) codeword generation with a multicarrier approach, 2) colluder weight estimation (CWE), and 3) advanced message symbol detection. We construct embedding codes with code spreading followed by multicarrier modulation. For CWE, we show that the weight estimation is analogous to channel response estimation, which can be solved by inserting pilot signals in the embedded fingerprint. As to advanced message symbol detection, we replace the traditional correlation-based detector with the maximal ratio combining detector and the parallel interference cancellation multiuser detector. The superior performance of the proposed fingerprinting system in terms of number of users/identified colluders and the bit-error probability of symbol detection is demonstrated by representative audio and video examples.
Wavelet descriptor of planar curves: theory and applications

By using the wavelet transform, the authors develop a hierarchical planar curve descriptor that decomposes a curve into components of different scales so that the coarsest scale components carry the global approximation information while the finer scale components contain the local detailed information. They show that the wavelet descriptor has many desirable properties such as multiresolution representation, invariance, uniqueness, stability, and spatial localization. A deformable wavelet descriptor is also proposed by interpreting the wavelet coefficients as random variables. The applications of the wavelet descriptor to character recognition and model-based contour extraction from low SNR images are examined. Numerical experiments are performed to illustrate the performance of the wavelet descriptor.
Design and Analysis of Prerake Ultrawideband Impulse Radio (PR-UWB-IR) With Turbo Outer Codes

The performance of a precoded ultrawideband impulse radio (UWB-IR) system using prerake as the inner code and superorthogonal turbo code (SOTC) or repetition code (RC) as outer codes is investigated in this paper. Prerake UWB-IR transmits information bits with time-reversed channel information. Due to the low transmission power of the UWB-IR, the sequence is repeated through outer coding. The prerake technique demands that the channel information be available to the transmitter. The tradeoff between the feedback channel information and several system performance metrics such as the length of the outer code and bit error rate (BER) is studied. It is shown that there exists a minimum feedback quantity required to achieve a target system performance in different communication scenarios. The optimal quantity of feedback channel knowledge and intersymbol interference (ISI) are investigated and verified by computer simulation.
Contour line extraction in a multi-modal field with sensor networks

A distributed approach to contour line extraction in a multi-modal field using wireless sensor networks is proposed in this work. In contrast with previous work on edge or boundary estimation, which is primarily concerned with the region of a certain phenomenon, contour lines offer more detailed information about the underlying phenomenon. To effectively utilize the limited resources of sensors, a cluster-based data fusion technique is adopted so that the phenomenon of interest can be monitored in the base station (BS) without demanding excessive raw data transmission. Simulation results are given to demonstrate the efficiency of the proposed approach. Furthermore, some analysis is conducted to understand the impact of the sensor density and noise on the performance of the proposed approach.
Information embedding in JPEG-2000 compressed images

Information embedding in JPEG-2000 compressed images is investigated in this research. The challenges of covert communication in this state-of-the-art image codec are analyzed and a steganographic scheme is then proposed to reliably embed high-volume data into the JPEG-2000 bitstream. A special mode of JPEG-2000 is employed, and its usage and functions are explained and justified. Experimental results are given to demonstrate the performance of the proposed algorithm.
Fast motion vector estimation using multiresolution-spatio-temporal correlations

We propose a new fast algorithm for block motion vector (MV) estimation based on the correlations of the MVs existing in spatially and temporally adjacent as well as hierarchically related blocks. We first establish a basic framework by introducing new algorithms based on spatial correlation and then spatio-temporal correlations before integrating them with a multiresolution scheme for the ultimate algorithm. The main idea is to effectively exploit the information obtained from the corresponding block at a coarser resolution level and spatio-temporal neighboring blocks at the same level in order to select a good set of initial MV candidates and then perform further local search to refine the MV result. We show with experimental results that, in comparison with the full search algorithm, the proposed algorithm achieves a speed-up factor ranging from 150 to 310 with only 2-7% mean square error (MSE) increase and a similar rate-distortion performance when applied to typical test video sequences.
Efficient Rotation Invariant Retrieval of Shapes with Applications in Medical Databases

Recognition of shapes in images is an important problem in computer vision with application in various medical problems, including robotic surgery and cell analysis. The similarity measures for such purpose must be robust to various transformations and modest occlusions. Transformations, such as scaling and translation can be handled easily by techniques through data representations or similarity measures. Rotation invariance is an inherently more difficult problem and can be handled through data representation, but at the expense of poor discrimination. Approaches which provide excellent discrimination require a complexity of O(n3) for each shape comparison. In this paper, we present a framework that provides a speedup over the slow but accurate approaches. The algorithm is inspired by the iterative deepening framework in artificial intelligence, by examining the data at increasingly fine levels of approximation until it is either considered irrelevant or submits to the full calculations. Although we examine the data several times at different levels of abstractions, because the time required for the last iteration dwarfs all others, this apparent redundancy is inconsequential. We show that our method provides at least a 3-4 orders of magnitude in speedup without generating any false dismissals
Fast and Flexible Tree Rendering with Enhanced Visibility Estimation

We present a set of techniques to simplify tree models for faster rendering while retaining their visual resemblance to the original model. This goal is achieved by setting a budget constraint of how many leaves shall be rendered, and we select leaves with higher possibilities to be visible to generate a simplified model for rendering. We first examine how leaf objects can be prioritized to provide a tree model suitable for a single viewing angle. The camerapsilas projected screen space is partitioned into several small regions to ensure that each region is guaranteed to be filled with a certain number of leaves. Each region selects higher priority leaves by utilizing the leaf objectspsila spatial relationship to the camera. Then, an iterative algorithm is proposed to allocate leaf objects at different viewing angles. The algorithm chooses different viewing positions for leaf allocation at each iteration with the goal of maximizing the resemblance to the original tree model at all possible angles. Three criteria taken in consideration for viewing angle selection are: distance, leaf normal, and unfilled pixel. Experimental results are provided to demonstrate time efficiency of the proposed techniques at the cost of little visual degradation.
Fast predictive integer- and half-pel motion search for interlaced video coding

A fast algorithm to perform integer- and half-pel motion search for interlaced video is proposed in this work. By exploiting the correlation between the frame- and the field-type integer-pel search, the proposed scheme can skip the sub-optimal integer-pel search type. Furthermore, based on the matching cost obtained from integer-pel search, the scheme will determine whether to perform the half-pel search. If the half-pel search is deemed necessary, the scheme is able to skip sub-optimal half-pel search points to further reduce the computational cost. Compared with the baseline scheme of the MVFAST algorithm for interlaced video, our new scheme can reduce up to 70% search points with around 0.1 /spl sim/ 0.2 db quality degradation.
A Content-Adaptive Up-Sampling Technique for Image Resolution Enhancement

A content adaptive technique is proposed to upsample an image to an output image of higher resolution in this work. The proposed technique is a block-based processing algorithm that offers the flexibility in choosing the most suitable up-sampling method for a particular block type. Block classification is first conducted in the DCT domain to categorized each image block into several types: smooth areas, textures, edges and others. For the plain background and smooth surfaces, simple patches are used to enlarge the image size without degrading the resultant visual quality. The unsharp masking method is applied to the textured region to preserve high frequency components. Since human eyes are more sensitive to edges, we adopt a more sophisticated technique to process edge blocks. That is, they are approximated by a facet model so that the image data at subpixel positions can be generated accordingly. A post-processing technique such as ID directional unsharp masking can be used to enhance edge sharpness furthermore. Experimental results are given to demonstrate the efficiency of the proposed technique.
2D enhanced intra prediction (2DEIP) for high definition image/video coding

An intra prediction (IP) scheme based on 2D geometrical manipulation, called 2DIP, was proposed in  to improve the line-based intra prediction (LIP) in H.264/AVC. In this work, we propose ways to reduce the complexity and enhance the efficiency of 2DIP and call the resultant scheme 2D enhanced intra prediction (2DEIP). These enhancements are achieved via block classification and translation vector prediction. It is shown by experimental results that the proposed 2DEIP method allows better prediction for images with complex textures. The average PSNR gain over the H.264/AVC intra prediction can be as high as 0.6 dB.
Semantic video content abstraction based on multiple cues

This research addresses the problem of automatically extracting video’s semantic structure and summarizing it in a hierarchical manner. Multiple media cues are employed in this procedure including visual, audio and text information. The generated hierarchy can provide us a compact yet meaningful abstraction of the video data similar to the conventional table-of-contents, which will facilitate user’s access to multimedia contents including browsing and retrieval. Preliminary experiments of integrating different media for hierarchically representing video semantics have yielded encouraging results.