Digital Video Data Research Articles

A Survey on Current Content based Image Retrieval Methods

Retrieving information from the Web is becoming a common practice for internet users. However, the size and heterogeneity of the Web challenge the effectiveness of classical information retrieval techniques. Content-based retrieval of images and video has become a hot research area. The reason for this is the fact that we need effective and efficient techniques that meet user requirements, to access large volumes of digital images and video data. This paper gives a brief survey of current CBIR (Content Based Image Retrieval) methods and technical achievement in this area. The survey includes a large number of papers covering the research aspects of system design and applications of CBIR, image feature representation and extraction, Multidimensional indexing. Furthermore future research directions are suggested.

Attacks on digital watermarks: classification, estimation based attacks, and benchmarks

Watermarking is a potential method for protection of ownership rights on digital audio, image, and video data. Benchmarks are used to evaluate the performance of different watermarking algorithms. For image watermarking, the Stirmark package is the most popular benchmark, and the best current algorithms perform well against it. However, results obtained by the Stirmark benchmark have to be handled carefully since Stirmark does not properly model the watermarking process and consequently is limited in its potential for impairing sophisticated image watermarking schemes. In this context, the goal of this article is threefold. First, we give an overview of the current attacking methods. Second, we describe attacks exploiting knowledge about the statistics of the original data and the embedded watermark. We propose a stochastic formulation of estimation-based attacks. Such attacks consist of two main stages: watermark estimation, exploitation of the estimated watermark to trick watermark detection or create ownership ambiguity. The full strength of estimation-based attacks can be achieved by introducing additional noise, where the attacker tries to combine the estimated watermark and the additive noise to impair watermark communication as much as possible while fulfilling a quality constraint on the attacked data. With a sophisticated quality constraint it is also possible to exploit human perception: the human auditory system in case of audio watermarks and the human visual system in case of image and video watermarks. Third, we discuss the current status of image watermarking benchmarks. We present Petitcolas'(see Electronic Imaging '99: Security and Watermarking of Multimedia Content, SPIE Proc., vol.3657, San Jose, CA, 1999) Stirmark benchmarking tool. Next, we consider the benchmark proposed by the University of Geneva Vision Group that contains more deliberate attacks. Finally, we summarize the current work of the European Certimark project, whose goal is to accelerate efforts from a number of research groups and companies in order to produce an improved ensemble of benchmarking tools.

Whiplash syndrome: kinematic factors influencing pain patterns.

The overall, local, and segmental kinematic responses of intact human cadaver head-neck complexes undergoing an inertia-type rear-end impact were quantified. High-speed, high-resolution digital video data of individual facet joint motions during the event were statistically evaluated. To deduce the potential for various vertebral column components to be exposed to adverse strains that could result in their participation as pain generators, and to evaluate the abnormal motions that occur during this traumatic event. The vertebral column is known to incur a nonphysiologic curvature during the application of an inertial-type rear-end impact. No previous studies, however, have quantified the local component motions (facet joint compression and sliding) that occur as a result of rear-impact loading. Intact human cadaver head-neck complexes underwent inertia-type rear-end impact with predominant moments in the sagittal plane. High-resolution digital video was used to track the motions of individual facet joints during the event. Localized angular motion changes at each vertebral segment were analyzed to quantify the abnormal curvature changes. Facet joint motions were analyzed statistically to obtain differences between anterior and posterior strains. The spine initially assumed an S-curve, with the upper spinal levels in flexion and the lower spinal levels in extension. The upper C-spine flexion occurred early in the event (approximately 60 ms) during the time the head maintained its static inertia. The lower cervical spine facet joints demonstrated statistically greater compressive motions in the dorsal aspect than in the ventral aspect, whereas the sliding anteroposterior motions were the same. The nonphysiologic kinematic responses during a whiplash impact may induce stresses in certain upper cervical neural structures or lower facet joints, resulting in possible compromise sufficient to elicit either neuropathic or nociceptive pain. These dynamic alterations of the upper level (occiput to C2) could impart potentially adverse forces to related neural structures, with subsequent development of a neuropathic pain process. The pinching of the lower facet joints may lead to potential for local tissue injury and nociceptive pain.

524 フォークボールの軌跡と速度変化(流体工学II)

Trajectories of fork-ball and straight ball were examined experimentally. Horizontal and vertical velocities of fork-ball and straight ball were calculated from the positions of those balls. Pictures of the straight ball and the fork-ball thrown by a baseball pitcher were taken by a video camera which was set perpendicular to the ball trajectory. Horizontal and vertical positions of forkball and straight ball were calculated from the digital video data by a personal computer. Similarly, horizontal and vertical velocities were calculated from the horizontal and vertical trajectories. Change of the velocities along the trajectories were examined.

Tracing Lineage of Array Data

Arrays are a common and important class of data in many applications. Arrays can model data such as digital images, digital video, scientific and experimental data, matrices, and finite element grids. Although array manipulations are diverse and domain-specific, they often exhibit structural regularities. This paper describes an algorithm called sub-pushdown to trace data lineage in such array computations. Lineage tracing is a type of data-flow analysis that relates parts of a result array to those parts of the argument (base) arrays that have bearings on the result array parts. Sub-pushdown can be used to trace data lineage in array-manipulating computations expressed in the Array Manipulation Language (AML) that was introduced previously. Sub-pushdown has several useful features. First, the lineage computation is expressed as an AML query. Second, it is not necessary to evaluate the AML lineage query to compute the array data lineage. Third, sub-pushdown never gives false-negative answers. Sub-pushdown has been implemented as part of the ArrayDB prototype array database system that we have built.

Optical observations of the orbital debris environment at NASA

To monitor the orbital debris environment and facilitate orbital debris modeling and forecasting, the Orbital Debris Program Office of the NASA Johnson Space Center operates two principal telescopes: the liquid mirror telescope (LMT) and the charge coupled device debris telescope (CDT). Both telescopes are maintained at the NASA Cloudcroft Observatory, a 15-meter dome at 2761-meter elevation near Cloudcroft, NM. The LMT became operational in October 1996. Approximately 580 hours of digital video data from the LMT have been collected and processed by an automated hardware/software system. Results from 504 hours are presented. This paper also presents the results of a study of the detection sensitivity of the LMT system as well as a new measurement-based model for estimating object size from LMT measurements. The CDT, the other principal component of the optical program, became operational in November 1997. The CDT is currently being used in a statistical survey of catalogued and uncataloguued debris in geosynchronous earth orbit. Approximately 180 nights worth of data have been collected and results from a portion of this data are presented. A new direction for the CDT is to investigate various regions in GEO that would contain debris from hypothesized break-ups.

Remote infrared acoustically triggered video monitoring unit

A remotely operable, infrared system for recording digital video and audio information immediately before, during, and after an acoustical event was developed. The primary application of this system to date has been the recording and documentation of effects of noise on wildlife, including Peregrine falcons (Falco peregrinus), Mexican spotted owls (Strix occidentalis lucida), and brown pelicans (Pelecanus occidentalis). The system triggers, records, and stores digital video and audio data on an IBM compatible computer running win9x. Serial communication with a Larson Davis sound-level meter allows a field video camera to store video and audible sound data on the computer. The need for field crew collection of bioacoustical effects data at sites with video acquisition systems is minimized. The video information reduces observation or interpretation bias in the data collection procedures. The systems can be maintained from remote locations using cellular modem technology and can be operated without being visited for extended periods. It is low powered and can be operated by a system of batteries and solar panels for indefinite field deployment. With the correct lens the system is capable of seeing in complete darkness up to 25 ft or as far away as 200 ft in the daytime.

Characterization of natural illuminants in forests and the use of digital video data to reconstruct illuminant spectra.

We describe illumination spectra in forests and show that they can be accurately recovered from recorded digital video images. Natural illuminant spectra of 238 samples measured in temperate forests were characterized by principal-component analysis. The spectra can be accurately approximated by the mean and the first two principal components. Compared with illumination under open skies, the loci of forest illuminants are displaced toward the green region in the chromaticity plots, and unlike open sky illumination they cannot be characterized by correlated color temperature. We show that it is possible to recover illuminant spectra accurately from digital video images by a linear least-squares-fit estimation technique. The use of digital video data in spectral analysis provides a promising new approach to the studies of the spatial and temporal variation of illumination in natural scenes and the understanding of color vision in natural environments.

Performance evaluation of transmission schemes for real-time traffic in a high-speed timed-token MAC network

The fast development of high-speed networks makes many real-time multimedia applications possible. These applications usually involve the transmission of massive amounts of digital video data, which requires the application of video image compression technology, under a stringent timing constraint. As a result, the transmission of the variable bit rate (VBR) traffic generated by the compression algorithms plays a very important role in meeting the real-time requirement of the applications. In this paper, we analyze the characteristics of the real-time traffic generated by Moving Pictures Experts Group (MPEG), which is one of the most notable video image compression standards, and evaluate four different transmission schemes for the real-time VBR traffic. In order to have a deterministic behavior and bounded message delays, we choose the timed token medium access control (MAC) protocol for the evaluation of our transmission schemes. Judging from our maximum bandwidth demand analysis, and after a series of intensive simulation experiments, the results reveal that in our best scenario, the performance improvement (PI) can be as high as 422% over the original default transmission scheme in terms of the number of video streams that can be supported in the network.

A SMPTE 292M/OC-48c Video Network Access Unit (VNAU)

Transmission of uncompressed high-speed digital SMPTE 292M video data is currently limited to relatively short distances: an electrical cable connection of up to 100 m or a direct optical fiber connection of up to 2 km. A prototype video network access unit (VNAU) implements transport of uncompressed SMPTE 292M serial video data packaged into asynchronous transmission mode (ATM) cells over a synchronous optical network (SONET) OC-48c link. This allows long-distance transport of uncompressed HDTV video using the public switched network. Network performance testing using a Tektronix VNAU, a FORE Systems switch, and the ATDNet was conducted at FORE Systems (Warrendale, PA) and the Naval Research Labs (Washington, DC). Network performance was monitored using control signals from the VNAU direct digital synthesizer (DDS), which allows a straightforward measurement of ATM cell latency without additional hardware.

The development of a digital video motion detection test set

This paper describes the current effort to develop a standardized data set, or suite of digital video sequences, that can be used for test and evaluation of digital video motion detectors (VMDs) for exterior applications. We have drawn from an extensive video database of typical application scenarios to assemble a comprehensive data set. These data, some existing for many years on analog videotape, have been converted to a reproducible digital format and edited to generate test sequences several minutes long for many scenarios. Sequences include non-alarm video, intrusions and nuisance alarm sources, taken with a variety of imaging sensors including monochrome CCD cameras and infrared (thermal) imaging cameras, under a variety of daytime and nighttime conditions. The paper presents an analysis of the variables and estimates the complexity of a thorough data set. Some of this video data test has been digitized for CD-ROM storage and playback. We are considering developing a DVD disk for possible use in screening and testing VMDs prior to government testing and deployment. In addition, this digital video data may be used by VMD developers for further refinement or customization of their product to meet specific requirements. These application scenarios may also be used to define the testing parameters for future procurement qualification. A personal computer may be used to play back either the CD-ROM or the DVD video data. A consumer electronics-style DVD player may be used to replay the DVD disk. This paper also discusses various aspects of digital video storage including formats, resolution, CD-ROM and DVD storage capacity, formats, editing and playback.

Watermarking digital image and video data. A state-of-the-art overview

The authors begin by discussing the need for watermarking and the requirements. They go on to discuss digital watermarking techniques based on correlation and techniques that are not based on correlation.

Models for motion-based video indexing and retrieval

With the rapid proliferation of multimedia applications that require video data management, it is becoming more desirable to provide proper video data indexing techniques capable of representing the rich semantics in video data. In real-time applications, the need for efficient query processing is another reason for the use of such techniques. We present models that use the object motion information in order to characterize the events to allow subsequent retrieval. Algorithms for different spatiotemporal search cases in terms of spatial and temporal translation and scale invariance have been developed using various signal and image processing techniques. We have developed a prototype video search engine, PICTURESQUE (pictorial information and content transformation unified retrieval engine for spatiotemporal queries) to verify the proposed methods. Development of such technology will enable true multimedia search engines that will enable indexing and searching of the digital video data based on its true content.

Video OCR: indexing digital news libraries by recognition of superimposed captions

The automatic extraction and recognition of news captions and annotations can be of great help locating topics of interest in digital news video libraries. To achieve this goal, we present a technique, called Video OCR (Optical Character Reader), which detects, extracts, and reads text areas in digital video data. In this paper, we address problems, describe the method by which Video OCR operates, and suggest applications for its use in digital news archives. To solve two problems of character recognition for videos, low-resolution characters and extremely complex backgrounds, we apply an interpolation filter, multiframe integration and character extraction filters. Character segmentation is performed by a recognition-based segmentation method, and intermediate character recognition results are used to improve the segmentation. We also include a method for locating text areas using text-like properties and the use of a language-based postprocessing technique to increase word recognition rates. The overall recognition results are satisfactory for use in news indexing. Performing Video OCR on news video and combining its results with other video understanding techniques will improve the overall understanding of the news video content.

40.1: A 2.6‐in. Poly‐Si TFT‐LCD HDTV Display with Monolithic Integrated 8‐bit Digital Data Drivers

AbstractA 2.6‐inch TFT‐LCD with 1920 × 1080 pixels which conforms to full advanced TV (ATV) format has been developed. An 8‐bit digital data driver with digital‐to‐analog converters (DACs), which can realize 256 level gray scale, has been integrated in monolithic driver. In addition, the circuit using the high mobility and low threshold voltage TFTs can operate directly on 80 MHz digital video data with 5 V supply voltage.

A digital high-performance multi-standard video data slicer

This paper describes the implementation of a multi-standard video data slicer. It was designed to process data of a variety of services like teletext, closed-caption etc. in multiple video norms like PAL and NTSC. For achieving high performance, the concept is completely digital and contains a self-adjusting equalizer.

Communication and Computing for Distributed Multimedia Systems

i»?i»?Guojun Lu Artech House, Cambridge, MA, 1996, 416 pp. ISBN 0-89006-884-4, $69.00 The telecommunications and computer industries are experiencing explosive growth. The most important trend is the convergence of the two in pursuing the promise of the information superhighway, a high-speed, ubiquitous, and seamless integrated services information infrastructure. The book Communication and Computing for Distributed Multimedia Systems by Lu focuses on a converged approach to development of distributed multimedia systems to meet the stringent requirements of multimedia computing and communications applications. It provides the first systematic discussion of issues and technology in developing networked multimedia systems. Each chapter covers issues related to an aspect of distributed multimedia systems and concludes with a summary, problems, and references. These help the readers better understand the text and provide insightful research directions for further investigations. The new concepts in each chapter are clearly defined, which clarifies the confusion caused by different new terms recently used in the literature. Chapter 1 introduces the fundamental concepts of multimedia computing and communications with sample applications. It also describes the different types of multimedia systems and the challenges of developing distributed multimedia systems. Chapter 2 presents the characteristics of multimedia data including digital audio, image, and video data. It then discusses the system requirements of processing multimedia data. It also includes a unique explanation of color specification and its role in achieving high picture quality, high compression ratio, and high information retrieval performance critical for future multimedia systems. Chapter 3 is devoted to the discussion of the principles and current techniques and standards for digital audio, image, and video compression which are very important, since multimedia data require a large storage to store and a large bandwidth to transmit. The challenge in developing distributed multimedia systems is to provide performance guarantees while using the network resources efficiently. Chapter 4 presents the end-to-end quality-of-service (QoS) framework for continuous media communication. In the next four chapters, the book discusses the support of QoS guarantee required at different layers of the communications network. Chapter 5 examines the characteristics of networks suitable for multimedia communication and discusses technical issues of QoS guarantees at the network layer. Chapter 6 covers the design issues of multimedia transport protocols and reviews a number of proposed multimedia transport protocols for the transport layer. Chapter 7 discusses the end-system support, including the support of hardware and operating systems, which is as important as network and transport support for multimedia communication. Chapter 8 is devoted to the discussion of a special type of end systems, multimedia servers. The book also covers techniques for networked multimedia synchronization and multimedia information indexing and retrieval. Chapter 9 discusses the requirements and mechanisms for intramedia and intermedia synchronization of multimedia data streams in distributed multimedia systems. Chapter 10 addresses how to organize multimedia information so that relevant information can be retrieved quickly from multimedia servers and techniques for indexing and retrieving multimedia information in distributed multimedia systems. The last chapter, Chapter 11, describes four current distributed multimedia systems: the World Wide Web (WWW), the Multicast Backbone (MBone), Video-on-Demand (VoD), and videoconferencing. The four systems can be considered as the primitive parts of the information superhighway. It concludes with a discussion of the general requirements and components of the information superhighway. From this book, the readers can learn about the special demands multimedia systems place on the computer architecture, storage, file system, operating system, and communications systems, and better understand the complex design challenges these components present. In addition, the readers can gain insight into current techniques and research efforts aimed at developing new computer architecture, operating systems, and communications systems to support multimedia. Looking ahead, the readers can catch a futuristic glimpse at the common networking paradigm evolved from the current telecommunications and computer networking models. Although the book has a relatively complete and balanced coverage of technical issues of distributed multimedia systems with QoS guarantees, it does not discuss two important issues that must be considered in development of distributed multimedia systems, security and user-friendly access. Hongchi Shi, University of Missouri-Columbia

Synchronous recording and review of oesophageal manometry and video fluoroscopy using a portable manometry recorder and PC with integrated digital video acquisition

We present the technical details of a new system for the synchronous recording and review of a combined oesophageal manometry and video fluoroscopic barium swallow examination. The system developed uses a portable manometry recorder and personal computer (PC) with an integrated digital video acquisition system. These are controlled using software to enable the real time capture of digital video and manometric data throughout the combined examination. The recorded pressure waveforms can then be synchronously displayed on a screen with the recorded digital video of the fluoroscopic barium swallow. This new tool enables both comparative measurement and detailed analysis of the relationship between visualized bolus transport and pressure measurements. It provides for a deeper understanding and improved clinical assessment of complex motility disorders over those obtained when these two modalities are applied separately. The system is easily incorporated into a clinical radiology suite and it is both user and patient friendly. It uses readily available computer hardware together with multimedia software and is a comparatively economical addition to the radiology suite with the manometry analysis available fulfilling the criteria laid down by the Clinical Associates Group of the British Society of Gastroenterology. Keywords: clinical environment, JPEG, oesophageal manometry, multimedia, real time system, synchronization

Bit reduction of DCT basis for transform coding

Extensive research has been carried out on transform coding using the discrete cosine transform (DCT) for compression of digital video data. Improvement of the video quality has been brought about by an increased number of pixels, such that a reduction of the time required for coding per pixel is highly desirable. When the multiplier coefficients in the coding operation or the values of the basis coefficients of the DCT are expressed as binary numbers, it is possible to reduce the operating time and simplify the process by using as few bits as possible. It is necessary to consider the constraint that the picture quality of the reconstructed video image should not be degraded by the reduction of the number of bits. In this paper, it is shown that the number of bits of the basis coefficients can be reduced under this constraint if quantization of the transform coefficients is taken into account. Also, the limiting value of the decrease of the number of bits in specific coding examples such as JPEG is determined. Finally, it is confirmed that the quality of the reconstructed video image changes very little even if the basis coefficients are represented by fewer bits than in previous schemes, provided that the reduction is within the limit presented in this paper. © 1997 Scripta Technica, Inc. Electron Comm Jpn Pt 1, 80(8): 81–91, 1997

Motion compensation for scalable decoder for drift reduction

In the communication and storage of digital video data, scalable coding has recently been attracting interest because not only can the data be compressed, but also a reduced image can be restored from a part of the compressed data. The restored image by scalable coding contains, in general, deterioration due to the quantization error, the resolution conversion error, and the drift error. Among those, the drift error is a result of the disagreement of the prediction signals due to motion compensation between the encoder and the decoder. It is more remarkable compared to the image deterioration by other factors since the error accumulates with the iteration of the prediction processes. From such a viewpoint, this paper proposes a new motion compensation method that can reduce the drift error. First, the generation process for the prediction signal is reduced to the multirate signal processing, and motion compensation is interpreted as a filtering process. Next, the ideal frequency characteristics of the motion compensation filter, when the drift error is reduced to zero, is specified. The design method for the motion compensation filter is described so that the ideal characteristics are approximated. Finally, the design motion compensation filter is combined into the scalable coding system and the drift reduction effect of the proposed method is verified. As a result of experiment for the natural image, the image quality improvement of approximately 2 dB is concluded. © 1997 Scripta Technica, Inc. Electron Comm Jpn Pt 3, 80(1): 47–58, 1997