Embedded captions in TV programs such as news broadcasts, documentaries and coverage of sports events provide important information on the underlying events. In digitalvideo libraries, such captions represent a highl...
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ISBN:
(纸本)0819420425
Embedded captions in TV programs such as news broadcasts, documentaries and coverage of sports events provide important information on the underlying events. In digitalvideo libraries, such captions represent a highly condensed form of key information on the contents of the video. In this paper we propose a scheme to automatically detect the presence of captions embedded in video frames. The proposed method operates on reduced image sequences which are efficiently reconstructed from compressed MPEG video and thus does not require full frame decompression. The detection, extraction and analysis of embedded captions help to capture the highlights of visual contents in video documents for better organization of video, to present succinctly the important messages embedded in the images, and to facilitate browsing, searching and retrieval of relevant clips.
Today's multimedia services, both at the server/head end and the client/consumer end, require high computational performance to support video encoding, decoding, and transcoding. Traditionally, the processing requ...
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Today's multimedia services, both at the server/head end and the client/consumer end, require high computational performance to support video encoding, decoding, and transcoding. Traditionally, the processing requirements have been met by application-specific processors (ASICs). What once were standalone single-function devices are now network-connected, multifunction service platforms-the Internet-ready digital television/video recorder/teleconference/game platform, for example. As a result, these platforms now must support multiple image formats, compression standards, and processing algorithms. Equator technologies has developed a high-performance, programmable system on a chip, the MAP-CA digital signal processor (DSP), to address this requirement. The MAP-CA DSP combines general-purpose reduced instruction set computer processing with high-performance image and signal processing in a very long instruction word framework. The chip is designed to replace hardwired ASICs in a variety of products, including digital head-end, networking products, and consumer applications. We present an analysis of the MAP-CA DSP architecture and provide several performance benchmarks with popular media processing applications.
digitalvideo traffic is inherently bursty for two reasons: inherent motion of objects and cameras, and the artifacts of compressionalgorithms. Because digitalvideo playback requires bandwidth guarantees from the un...
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digitalvideo traffic is inherently bursty for two reasons: inherent motion of objects and cameras, and the artifacts of compressionalgorithms. Because digitalvideo playback requires bandwidth guarantees from the underlying I/O and network systems, the bursty nature of video traffic forces the bandwidth reservations to be made at the level of peak data rates rather than average data rates. This work addresses the burstiness problem in digitalvideo traffic by proposing changes to the MPEG compression/decompression algorithm. The resulting algorithm, block-by-block (BBB) difference coding, successfully minimizes the difference between peak and average bit rates by a factor of 2 to 3 in average, without compromising the compression efficiency, coding speed and video quality.
Due to the increasing number of new services and devices that allow the creation, distribution and consumption of video content, the amount of video information being transmitted all over the world is constantly growi...
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Due to the increasing number of new services and devices that allow the creation, distribution and consumption of video content, the amount of video information being transmitted all over the world is constantly growing. videocompression technology is essential to cope with the ever increasing volume of digitalvideo data being distributed in today's networks, as more e cient videocompression techniques allow support for higher volumes of video data under the same memory/bandwidth constraints. This is especially relevant with the introduction of new and more immersive video formats associated with signi cantly higher amounts of data. In this thesis, novel techniques for improving the e ciency of current and future video coding technologies are investigated. Several aspects that in uence the way conventional video coding methods work are considered. In particular, the properties and limitations of the Human Visual System are exploited to tune the performance of video encoders towards better subjective quality. Additionally, it is shown how the visibility of speci c types of visual artefacts can be prevented during the video encoding process, in order to avoid subjective quality degradations in the compressed content. Techniques for higher videocompression e ciency are also explored, targeting to improve the compression capabilities of state-of-the-art video coding standards. Finally, the application of video coding technologies to practical use-cases is considered. Accurate estimation models are devised to control the encoding time and bit rate associated with compressed video signals, in order to meet speci c encoding time and transmission time restrictions.
The development of video quality metrics and perceptual video quality metrics has been a well established pursuit for more than 25 years. The body of work has been seen to be most relevant for improving the performanc...
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ISBN:
(数字)9781510620766
ISBN:
(纸本)9781510620766
The development of video quality metrics and perceptual video quality metrics has been a well established pursuit for more than 25 years. The body of work has been seen to be most relevant for improving the performance of visual compressionalgorithms. However, modeling the human perception of video with an algorithm of some sort is notoriously complicated. As a result the perceptual coding of video remains challenging and no standards have incorporated perceptual video quality metrics within their specification. In this paper we present the use of video metrics at the system level of a video processing pipeline. We show that it is possible to combine the artefact detection and correction process by posing the problem as a classification exercise. We also present the use of video metrics as part of a classical testing pipeline for software infrastructure, but here it is sensitive to the perceived quality in picture degradation.
Traditional objective measurements are of limited effectiveness in predicting the quality of compressed images. Subjective assessment is the most reliable method of evaluation of compression systems performance now. B...
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ISBN:
(纸本)0819423564
Traditional objective measurements are of limited effectiveness in predicting the quality of compressed images. Subjective assessment is the most reliable method of evaluation of compression systems performance now. But subjective assessment is time consuming. That is why it is important to simplify the procedure of subjective measurement. To achieve it one may use the method of paired comparisons. This paper describes applications of the method of paired comparisons in the field of assessment of concatenated compression systems.
Embedding information into multimedia data is a topic that has gained increasing attention recently. For video broadcast applications, watermarking of video, and especially of already encoded video, is interesting. We...
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ISBN:
(纸本)0819423564
Embedding information into multimedia data is a topic that has gained increasing attention recently. For video broadcast applications, watermarking of video, and especially of already encoded video, is interesting. We present a scheme for robust interoperable watermarking of MPEG-2 encoded video. The watermark is embedded either into the uncoded video or into the MPEG-2 bitstream, and can be retrieved from the decoded video. The scheme working on encoded video is of much lower complexity than a complete decoding process followed by watermarking in the pixel domain and re-encoding. Although an existing MPEG-2 bitstream is partly altered, the scheme avoids drift problems. The scheme has been implemented and practical results show that a robust watermark can be embedded into MPEG encoded video which can be used to transmit arbitrary binary information at a data rate of several bytes/second.
video processing algorithms are computationally intensive and place stringent requirements on performance and efficiency of memory bandwidth and capacity. As such, efficient hardware accelerations are inevitable for f...
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video processing algorithms are computationally intensive and place stringent requirements on performance and efficiency of memory bandwidth and capacity. As such, efficient hardware accelerations are inevitable for fast video processing systems. In this paper, we propose resource- and power-optimized FPGA-based configurable architecture for video object detection by integrating noise estimation, Mixture-of-Gaussian background modeling, motion detection, and thresholding. Due to large amount of background modeling parameters, we propose a novel Gaussian parameter compression technique suitable for resource- and power-constraint embedded video systems. The proposed architecture is simulated, synthesized and verified for its functionality, accuracy and performance on a Virtex-5 FPGA-based embedded platform by directly interfacing to a digitalvideo input. Intentional exploitation of heterogeneous resources in FPGAs, and advanced design techniques such as heavy pipelining and data parallelism yield real-time processing of HD-1080p video streams at 30 frames per second. Objective and subjective evaluations to existing hardware-based methods show that the proposed architecture obtains orders of magnitude performance improvements, while utilizing minimal hardware resources. This work is an early attempt to devise a complete video surveillance system onto a stand-alone resource-constraint FPGA-based smart camera.
compression of moving images has opened unprecedented opportunities of transmission and storage of digitalvideo. Extraordinary performance of today's video codecs is a result of tens of years of work on the devel...
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ISBN:
(纸本)9783319472744;9783319472737
compression of moving images has opened unprecedented opportunities of transmission and storage of digitalvideo. Extraordinary performance of today's video codecs is a result of tens of years of work on the development of methods of data encoding. This paper is an attempt to show this history of development. It highlights the history of individual algorithms of data encoding as well as the evolution of videocompressiontechnologies as a whole. With the development of successive technologies also functionalities of codecs were evolving, which make also the topic of the paper. The paper ends the attempt of authors' forecasting about the future evolution of videocompressiontechnologies.
Motion estimation is a key component of any modern video codec. Our understanding of motion and the estimation of motion from video has come a very long way since 2000. More than 135 different algorithms have been rec...
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ISBN:
(数字)9781510620766
ISBN:
(纸本)9781510620766
Motion estimation is a key component of any modern video codec. Our understanding of motion and the estimation of motion from video has come a very long way since 2000. More than 135 different algorithms have been recently reviewed by Scharstein et al http://***/flow/. These new algorithms differ markedly from Block Matching which has been the mainstay of videocompression for some time. This paper presents comparisons of H.264 and MP4 compression using different motion estimation methods. In so doing we present as well methods for adapting pre-computed motion fields for use within a codec. We do not observe significant gains to be had with the methods chosen w.r.t. Rate Distortion tradeoffs but the results reflect a significantly more complex interrelationship between motion and compression than would be expected. There remains much more to be done to improve the coverage of this comparison to the emerging standards but these initial results show that there is value in these explorations.
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