QoS Control Strategies for High-Quality Video Processing

Video processing in software is often characterized by highly fluctuating, content-dependent processing times, and a limited tolerance for deadline misses. We present an approach that allows close-to-average-case resource allocation to a single video processing task, based on asynchronous, scalable processing, and QoS adaptation. The QoS adaptation balances different QoS parameters that can be tuned, based on user-perception experiments: picture quality, deadline misses, and quality changes. We model the balancing problem as a discrete stochastic decision problem, and propose two solution strategies, based on a Markov decision process and reinforcement learning, respectively. We enhance both strategies with a compensation for structural (non-stochastic) load fluctuations. Finally, we validate our approach by means of simulation experiments, and conclude that both enhanced strategies perform close to the theoretical optimum.Clemens Wüst received the M.Sc. degree in mathematics with honors from the University of Groningen, The Netherlands. Since then, he has been with the Philips Research Laboratories in Eindhoven, The Netherlands, where he has been working mainly on QoS for resource-constrained real-time systems using stochastic optimization techniques. Currently, he is pursuing a Ph.D. degree at the Technische Universiteit Eindhoven.Liesbeth Steffens received her M.Sc. from Utrecht University (NL) in 1972. She spent most of her professional life in Philips Research in Eindhoven. She contributed to the design of a real-time distributed operating system, a video-on-demand server, a DVD player, a set-top box, and a QoS-based Resource-Management framework for streaming video. Her current focus is on characterization of resource requirements, resource reservation, and system-on-chip infrastructure.Wim F. J. Verhaegh received the mathematical engineering degree with honors in 1990 from the Technische Universiteit Eindhoven, The Netherlands. Since then, he is with the Philips Research Laboratories in Eindhoven, The Netherlands. From 1990 until 1998, he has been a member of the department Digital VLSI, where he has been working on high-level synthesis of DSP systems for video applications, with the emphasis on scheduling problems and techniques. Based on this work, he received a Ph.D. degree in 1995 from the Technische Universiteit Eindhoven. Since 1998, he is working on various optimization aspects of multimedia systems, networks, and applications. On the one hand, this concerns application-level resource management and scheduling, for optimization of quality of service of multimedia systems. On the other hand, this concerns adaptive algorithms and machine learning algorithms for user interaction issues, such as content filtering and automatic playlist generation.Reinder J. Bril received a B.Sc. and a M.Sc. (both with honors) from the Department of Electrical Engineering of the University of Twente, and a Ph.D. from the Technische Universiteit Eindhoven (TU/e), The Netherlands. He started his professional career at the Delft University of technology in the Department of Electrical Engineering. From May 1985 till August 2004, he has been with Philips. He has worked in both Philips Research as well as Philips Business Units, on various topics, including fault-tolerance, formal specifications, and software architecture analysis, and in different application domains. The last five years, he worked at Philips Research Laboratories Eindhoven (PRLE), the Netherlands, in the area of Quality of Service (QoS) for consumer devices, with a focus on dynamic resource management in receivers in broadcast environments (such as digital TV-sets and set-top boxes). In September 2004, he made a transfer to the Technische Universiteit Eindhoven (TU/e), Department of Mathematics and Computer Science, Group System Architecture and Networking (SAN), i.e. back to the academic world, after 19 years in industry.Christian Hentschel received his Dr.-Ing. (Ph.D.) in 1989 and Dr.-Ing. habil. in 1996 at the University of Technology in Braunschweig, Germany. He worked on digital video signal processing with focus on quality improvement. In 1995, he joined Philips Research in Briarcliff Manor, USA, where he headed a research project on moiré analysis and suppression for CRT based displays. In 1997, he moved to Philips Research in Eindhoven, The Netherlands, leading a cluster for Programmable Video Architectures. Later he held a position of a Principal Scientist and coordinated a project on scalable media processing with dynamic resource control between different research laboratories. In 2003, he became a full professor at the Brandenburg University of Technology in Cottbus, Germany. Currently he chairs the department of Media Technology. He is a member of the Technical Committee of the International Conference on Consumer Electronics (IEEE) and a member of the FKTG in Germany.     

A tamper-proof and lightweight authentication scheme

We present a tamper-proof and lightweight challenge-response authentication scheme, based on 2-level noisy Physically Unclonable Functions (PUF). We present a security reduction, which shows the scheme to be secure against passive attacks, provided that it is hard to learn a threshold of halfspaces under the uniform distribution. Furthermore, we provide an extensive analysis of PUFs. In particular, we thoroughly derive a linear model for delay based PUFs, and finally we explore extensions of PUFs to produce efficient and tamper-resilient n-to-n mappings.     

Designing systolic,distributed buffers with bounded response time

Several buffer designs are derived by applying a design methodology that is based on so-called abstract states. Abstract states are euivalence classes of communication histories. These abstract states are very useful in the verification of program transformations, since they facilitate the definition of a function mapping the states of the transformed automaton onto the states of the original one. Three kinds of bufferes are discussed: the stack, the first-in first-out queue, and the priority queue. The designs are systolic and offer bounded response time, which means that all permissible communications are accepted within a time bounded by a constant. The design of the stack offers maximum storage utilization as well. We show that the properties of bounded response time and maximum storage utilization cannot be combined in distributed systolic queues. Joep L.W. Kessels received an M.Sc. (Honors) degree in electrical engineering from the Eindhoven University of Technology, The Netherlands, in 1967. In 1969 he joined the Philips Research Laboratories in Eindhoven, where he has been involved in three major projects in the following research areas: applicative programming, distributed processing, and local area networks. Currently, he is engaged in the formal derivation of VLSI designs. His main research interests are design methodology and distributed processing. Martin Rem obtained an M.Sc. degree in mathematics at the University of Amsterdam in 1971 and a Ph.D. degree in computing science at the Eindhoven University of Technology in 1976. He is currently professor of mathematics and computing science at Eindhoven and part-time visiting professor at California Institute of Technology. Professor Rem is consultant for Philips Research and editor of Science of Computer Programming and Integration.     

Reporting Leaders and Followers among Trajectories of Moving Point Objects

Widespread availability of location aware devices (such as GPS receivers) promotes capture of detailed movement trajectories of people, animals, vehicles and other moving objects, opening new options for a better understanding of the processes involved. In this paper we investigate spatio-temporal movement patterns in large tracking data sets. We present a natural definition of the pattern ‘one object is leading others’, which is based on behavioural patterns discussed in the behavioural ecology literature. Such leadership patterns can be characterised by a minimum time length for which they have to exist and by a minimum number of entities involved in the pattern. Furthermore, we distinguish two models (discrete and continuous) of the time axis for which patterns can start and end. For all variants of these leadership patterns, we describe algorithms for their detection, given the trajectories of a group of moving entities. A theoretical analysis as well as experiments show that these algorithms efficiently report leadership patterns.

Efficient and Lightweight FPGA-based Hybrid PUFs with Improved Performance

In recent years, Physically Unclonable Functions (PUFs) have emerged as a promising technique for hardware based security primitives because of its inherent uniqueness and low cost. In this paper, we present an area efficient hybrid PUF design on field-programmable gate array (FPGA). Our approach combines units of conventional RS Latch-based PUF (RS-LPUF) and Arbiter-based PUF (A-PUF) which is then augmented by the programmable delay lines (PDLs) and Temporal Majority Voting (TMV) for performance enhancement. The area of the hybrid PUF is relatively high when compared to few conventional PUF designs, but is significantly small when compared to other composite and hybrid PUF designs reported so far. The measured results on the Xilinx Spartan-6 FPGA demonstrate PUF signatures exhibits good uniqueness, reliability, and uniformity with no occurrence of bit-aliasing.     

Variable frame rate control jerkiness-driven

We are introducing a real-time variable frame rate control scheme capable of optimizing both spatial and temporal video qualities. It traces the motion of incoming video frames and automatically tunes the outgoing frame rate according to the level of jerkiness acceptable by the user. The control scheme was conceived within the framework of mobile communications, which require an optimum use of both the available bandwidth and terminal resources. We have designed and implemented a video transcoding architecture which supports our frame rate control. The transcoder has been developed at the Coritel laboratories, Rome, Italy (Coritel is a research consortium managed by Ericsson Lab, Italy, and the University of Rome La Sapienza), while the visual tests were carried out at the ISCOM laboratory, Italian Communication Ministry, Rome, Italy. The proposed transcoding architecture is compatible with the constraints of real-time communications and it has been extensively tested under a wide range of conditions. We then present a subjective assessment of our solution carried out in a fully equipped professional laboratory. Within this assessment a number of non-expert viewers were asked to express their preference when watching side by side the same video, coded at a variable frame rate and at a fixed frame rate. Results show that in most cases a variable frame rate control based on a dynamic bit/frame allocation scheme might substantially improve video quality perceived by viewers.

Video JET: packet loss-resilient video joint encryption and transmission based on media-hash-embedded residual data

Media encryption technologies actively play the first line of defense in securing the access of multimedia data. Traditional cryptographic encryption can achieve provable security but is unfortunately sensitive to a single bit error, which will cause an unreliable packet to be dropped creating packet loss. In order to achieve robust media encryption, the requirement of error resilience can be achieved with error-resilient media transmission. This study proposes a video joint encryption and transmission (video JET) scheme by exploiting media hash-embedded residual data to achieve motion estimation and compensation for recovering lost packets, while maintaining format compliance and cryptographic provable security. Interestingly, since video block hash preserves the condensed content to facilitate search of similar blocks, motion estimation is implicitly performed through robust media hash matching – which is the unique characteristic of our method. We analyze and compare the performance of resilience to (bursty) packet loss between the proposed method and forward error correction (FEC), which has been extensively employed to protect video packets over error-prone networks. The feasibility of our packet loss-resilient video JET approach is further demonstrated through experimental results.

ScaleSpaceViz: α-Scale spaces in practice

Kernels of the so-called α-scale space have the undesirable property of having no closed-form representation in the spatial domain, despite their simple closed-form expression in the Fourier domain. This obstructs spatial convolution or recursive implementation. For this reason an approximation of the 2D α-kernel in the spatial domain is presented using the well-known Gaussian kernel and the Poisson kernel. Experiments show good results, with maximum relative errors of less than 2.4%. The approximation has been successfully implemented in a program for visualizing α-scale spaces. Some examples of practical applications with scale space feature points using the proposed approximation are given. The text was submitted by the authors in English. Frans Kanters received his MSc degree in Electrical Engineering in 2002 from the Eindhoven University of Technology in the Netherlands. Currently he is working on his PhD at the Biomedical Imaging and Informatics group at the Eindhoven University of Technology. His PhD work is part of the “Deep Structure, Singularities, and Computer Vision (DSSCV)” project sponsored by the European Union. His research interests include scale space theory, image reconstruction, image processing algorithms, and hardware implementations thereof. Luc Florack received his MSc degree in theoretical physics in 1989 and his PhD degree cum laude in 1993 with a thesis on image structure, both from Utrecht University, the Netherlands. During the period from 1994 to 1995, he was an ERCIM/HCM research fellow at INRIA Sophia-Antipolis, France, and IN-ESC Aveiro, Portugal. In 1996 he was an assistant research professor at DIKU, Copenhagen, Denmark, on a grant from the Danish Research Council. From 1997 to June 2001, he was an assistant research professor at Utrecht University in the Department of Mathematics and Computer Science. Since June 1, 2001, he has been working as an assistant professor and, then, as an associate professor at Eindhoven University of Technology, Department of Biomedical Engineering. His interest includes all multiscale structural aspects of signals, images, and movies and their applications to imaging and vision. Remco Duits received his MSc degree (cum laude) in Mathematics in 2001 from the Eindhoven University of Technology, the Netherlands. Today he is a PhD student at the Department of Biomedical Engineering at the Eindhoven University of Technology on the subject of multiscale perceptual organization. His interest subtends functional analysis, group theory, partial differential equations, multiscale representations and their applications to biomedical imaging and vision, perceptual grouping. Currently, he is finishing his thesis “Perceptual Organization in Image Analysis (A Mathematical Approach Based on Scale, Orientation and Curvature).” During his PhD work, several of his submissions at conferences were chosen as selected or best papers—in particular, at the PRIA 2004 conference on pattern recognition and image analysis in St. Petersburg, where he received a best paper award (second place) for his work on invertible orientation scores. Bram Platel received his Masters Degree cum laude in biomedical engineering from the Eindhoven University of Technology in 2002. His research interests include image matching, scale space theory, catastrophe theory, and image-describing graph constructions. Currently he is working on his PhD in the Biomedical Imaging and Informatics group at the Eindhoven University of Technology. Bart M. ter Haar Romany is full professor in Biomedical Image Analysis at the Department of Biomedical Engineering at Eindhoven University of Technology. He has been in this position since 2001. He received a MSc in Applied Physics from Delft University of Technology in 1978, and a PhD on neuromuscular nonlinearities from Utrecht University in 1983. After being the principal physicist of the Utrecht University Hospital Radiology Department, in 1989 he joined the department of Medical Imaging at Utrecht University as an associate professor. His interests are mathematical aspects of visual perception, in particular linear and non-linear scale-space theory, computer vision applications, and all aspects of medical imaging. He is author of numerous papers and book chapters on these issues; he edited a book on non-linear diffusion theory and is author of an interactive tutorial book on scale-space theory in computer vision. He has initiated a number of international collaborations on these subjects. He is an active teacher in international courses, a senior member of IEEE, and IEEE Chapter Tutorial Speaker. He is chairman of the Dutch Biophysical Society.     

Controller Area Network (CAN) schedulability analysis: Refuted,revisited and revised

Controller Area Network (CAN) is used extensively in automotive applications, with in excess of 400 million CAN enabled microcontrollers manufactured each year. In 1994 schedulability analysis was developed for CAN, showing how worst-case response times of CAN messages could be calculated and hence guarantees provided that message response times would not exceed their deadlines. This seminal research has been cited in over 200 subsequent papers and transferred to industry in the form of commercial CAN schedulability analysis tools. These tools have been used by a large number of major automotive manufacturers in the design of in-vehicle networks for a wide range of cars, millions of which have been manufactured during the last decade. This paper shows that the original schedulability analysis given for CAN messages is flawed. It may provide guarantees for messages that will in fact miss their deadlines in the worst-case. This paper provides revised analysis resolving the problems with the original approach. Further, it highlights that the priority assignment policy, previously claimed to be optimal for CAN, is not in fact optimal and cites a method of obtaining an optimal priority ordering that is applicable to CAN. The paper discusses the possible impact on commercial CAN systems designed and developed using flawed schedulability analysis and makes recommendations for the revision of CAN schedulability analysis tools. Robert I. Davis received a DPhil in Computer Science from the University of York in 1995. Since then he has founded three start-up companies, all of which have succeeded in transferring real-time systems research into commercial product. At Northern Real-Time Technologies Ltd. (1995–1997) he was responsible for development of the Volcano CAN software library. At LiveDevices Ltd. (1997–2001) he was responsible for development of the Real-Time Architect suite of products, including an OSEK RTOS and schedulability analysis tools. In 2002, Robert returned to the University of York, and in 2004 he was involved in setting up a spin out company, Rapita Systems Ltd., aimed at transferring worst-case execution time analysis technology into industry. Robert is a member of the Real-Time Systems Research Group at the University of York, and a director of Rapita Systems Ltd. His research interests include scheduling algorithms and schedulability analysis for real-time systems. Alan Burns is head of the Real-Time Systems Research Group at the University of York. His research interests cover a number of aspects of real-time systems including the assessment of languages for use in the real-time domain, distributed operating systems, the formal specification of scheduling algorithms and implementation strategies, and the design of dependable user interfaces to real-time applications. He has authored/co-authored over 370 papers and 10 books, with a large proportion of them concentrating on real-time systems and the Ada programming language. Professor Burns has been actively involved in the creation of the Ravenscar Profile, a subset of Ada”s tasking model, designed to enable the analysis of real-time programs and their timing properties. Reinder J. Bril received a B.Sc. and an M.Sc. (both with honours) from the University of Twente, and a Ph.D. from the Technische Universiteit Eindhoven, the Netherlands. He started his professional career in January 1984 at the Delft University of Technology. From May 1985 until August 2004, he was with Philips, and worked in both Philips Research as well as Philips’ Business Units. He worked on various topics, including fault tolerance, formal specifications, software architecture analysis, and dynamic resource management, and in different application domains, e.g. high-volume electronics consumer products and (low volume) professional systems. In September 2004, he made a transfer back to the academic world, to the System Architecture and Networking (SAN) group of the Mathematics and Computer Science department of the Technische Universiteit Eindhoven. His main research interests are currently in the area of reservation-based resource management for networked embedded systems with real-time constraints. Johan J. Lukkien has been head of the System Architecture and Networking Research group at Eindhoven University of Technology since 2002. He received an M.Sc. and a Ph.D. from Groningen University in the Netherlands. In 1991, he joined Eindhoven University, after two years leave at the California Institute of Technology. His research interests include the design and performance analysis of parallel and distributed systems. Until 2000 he was involved in large-scale simulations in physics and chemistry. Since 2000, his research focus has shifted to the application domain of networked resource-constrained embedded systems. Contributions of the SAN group are in the area of component-based middleware for resource-constrained devices, distributed co-ordination, Quality of Service in networked systems and schedulability analysis in real-time systems.