A new video segmentation algorithm using a combined segmentation measure for content-based coding is presented. The combined segmentation measure is a weighted sum of intensity, motion, and a change segmentation measu...
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A new video segmentation algorithm using a combined segmentation measure for content-based coding is presented. The combined segmentation measure is a weighted sum of intensity, motion, and a change segmentation measure. The change segmentation measure is defined from a change image, which is obtained from the proposed change detector. The proposed change detector performs morphological erosion filtering to eliminate many inaccurate components, included in the resulting image obtained from a conventional change detector. Since the change segmentation measure is defined as an absolute change value difference between a pixel and its neighboring region, it can be an efficient segmentation measure for the accurate segmentation of neighboring moving objects and static background regions. Therefore, the proposed combined segmentation measure can determine exact boundaries even though the estimated motion vectors around the boundaries of moving objects and static background regions are inaccurate and the intensities around the boundaries are similar. From the experimental results for a video segmentation, since the combined segmentation measure can accurately segment the boundaries between moving objects and static background regions, the motion compensated images produced by the proposed segmentation algorithm show improved image quality compared to the conventional segmentation. (C) 2000 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(00)01208-3].
To provide multimedia applications with new functionalities, such as content-based interactivity and scalability, the new video coding standard MPEG-4 relies on a content-based representation. This requires a prior de...
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To provide multimedia applications with new functionalities, such as content-based interactivity and scalability, the new video coding standard MPEG-4 relies on a content-based representation. This requires a prior decomposition of sequences into semantically meaningful, physical objects. We formulate this problem as one of separating foreground objects from the background based on motion information. For the object of interest, a two-dimensional binary model is derived and tracked throughout the sequence, The model points consist of edge pixels detected by the Canny operator. To accommodate rotation and changes in shape of the hacked object, the model is updated every frame. These binary models then guide the actual video object plane (VOP) extraction. Thanks to our new boundary postprocessor and the excellent edge localization properties of the Canny operator, the resulting VOP contours are very accurate. Both the model initialization and update stages exploit motion information. The main assumption underlying our approach is the existence of a dominant global motion that can be assigned to the background. Areas that do not follow this background motion indicate the presence of independently moving physical objects. Two alternative methods to identify such objects are presented. The first one employs a morphological motion filter with a new filter criterion, which measures the deviation of the locally estimated optical how from the corresponding global motion. The second method computes a change detection mask by taking the difference between consecutive frames. The first version is more suitable for sequences with little motion, whereas the second version is better at dealing with faster moving or changing objects. Experimental results demonstrate the performance of our algorithm.
Human face images form the important database in banks, security kiosks, police departments and they are also found in abundance in day-to-day life. In these databases the important content, of course is the face regi...
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ISBN:
(纸本)0819437034
Human face images form the important database in banks, security kiosks, police departments and they are also found in abundance in day-to-day life. In these databases the important content, of course is the face region. In this paper, we present two highly efficient methods for compressing face images. The first method, which is lossy, detects the human faces in the wavelet domain for discriminative quantization to achieve high perceptual quality content-based image compression. This method gives superior subjective performance over JPEG standard without sacrificing the performance in the rate-distortion spectrum. The second method, which is lossy as well as lossless, also detects the human faces in the wavelet domain so that lossy/lossless mode can be selected dynamically for compression. This method gives the best solution to applications which can not tolerate losses for face regions. The method improves the overall coding efficiency by adapting lossy mode for non-face regions instead of coding entire image in lossless mode.
The increasing spread of digital technology in many areas, notably telecommunications, and entertainment (TV/cinema), is nowadays changing the production, delivery, and consumption paradigms for multimedia information...
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The increasing spread of digital technology in many areas, notably telecommunications, and entertainment (TV/cinema), is nowadays changing the production, delivery, and consumption paradigms for multimedia information. New applications with critical requirements in terms of content-based interactivity are imminent, motivating the evolution of the models used for data representation, notably for coding and indexing. The emerging MPEG-4 and MPEG-7 standards are the recognition, by the industry, of these upcoming needs. This paper addresses the problem of video analysis for content-based coding and indexing in the context of a changing technological landscape. The main video analysis objectives and constraints are identified, the role of user interaction is studied, and some application examples are described. (C) 1998 Elsevier Science B.V. All rights reserved.
content-based coding, which independently codes the objects included in a picture, has recently attracted considerable attention fur its property of enabling object-based editing of still and motion pictures. In conte...
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ISBN:
(纸本)0819427497
content-based coding, which independently codes the objects included in a picture, has recently attracted considerable attention fur its property of enabling object-based editing of still and motion pictures. In content-based coding, it is required to code arbitrarily shaped objects. Therefore, it is necessary to apply 2D-DCT to 8x8 blocks that include object boundaries. Padding is a technique that enables coding of such blocks by assigning imaginary values to the pixels that are not included in the object. Additionally, padding prevents the increase of the high frequency DCT coefficients which is caused by the discontinuous object boundary. In this Raper, a new padding method named Symmetric Padding, which provides high coding efficiency with a simple copy-and-paste procedure, is proposed. Additionally a content-based 2D-DCT coding method, which changes the padding method and the scanning method according to the features of the object shape, is proposed. Due to the increase of the number of zero DCT coefficients, the proposed method shows better coding performance than conventional method, especially, at high bit rates.
This paper presents an efficient VLSI architecture design of MPEG-4 shape coding, which is the key technology for supporting the content-based functionality of the MPEG-4 Video standard. The real-time constraint of MP...
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This paper presents an efficient VLSI architecture design of MPEG-4 shape coding, which is the key technology for supporting the content-based functionality of the MPEG-4 Video standard. The real-time constraint of MPEG-4 shape coding leads to a heavy computational bottleneck on today's computer architectures. To overcome this problem, design analysis and optimization of MPEG-4 shape coding are addressed in this paper. By utilizing the RISC-based model, computational behaviors of the MPEG-4 shape coding tool are carefully examined and analyzed. The characteristic of a large amount of bit-level data processing and data transfer of MPEG-4 shape coding motivates us the optimization of bit-level data operations. Applying the data-flow optimization and data reuse,techniques, bit-level computation-efficient architectures, such as data-dispatch-based binary-shaped motion estimation, the delay-line model, and configurable context-based arithmetic coding, are designed to accelerate bit-level processing. These hardware blocks are integrated and scheduled in a very efficient data flow to achieve real-time performance for MPEG-4 CPL2 specification at 23.5-MHz clock rate. The system architecture is implemented using Verilog HDL and synthesized with a 0.35-mum four-layer CMOS standard library.
Our ability to predict fire behavior and its effects on our lives has greatly improved over the past quarter century. Numerous scientific advancements have introduced new approaches and tools for the fire safety-relat...
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Our ability to predict fire behavior and its effects on our lives has greatly improved over the past quarter century. Numerous scientific advancements have introduced new approaches and tools for the fire safety-related design of both the built environment and the development of new products.' However, many of these new methods are not currently used on a routine basis. A growing number of individuals in the fire safety community think that our current fire safety design and approval process, coupled with the rigid make-up of our existing codes and standards, inhibit the greater application of these new methods.(2) While many factors such as resistance to change and the potential misapplication of calculation tools, can account for this inhibiting effect, this paper focuses on the role of codes and standards and discusses how they might better serve the transfer and application of new technology.
This article describes the current status and future directions of the emerging ISO MPEG-4 audiovisual coding standard. The article first presents an overview of the different aspects of the standard and then focuses ...
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This article describes the current status and future directions of the emerging ISO MPEG-4 audiovisual coding standard. The article first presents an overview of the different aspects of the standard and then focuses on the video coding aspects, The current status of the Video Verification Model (VM) (a completely defined encoder and decoder specification) is described in detail and its performance is presented. The new functionalities supported by this emerging standard and their potential applications are highlighted. (C) 1997 John Wiley & Sons, Inc.
Research in very low-bit rate coding has made significant advancements in the past few years. Most recently, the introduction of the MPEG-4 proposal has motivated a wide variety of approaches aimed al achieving a new ...
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Research in very low-bit rate coding has made significant advancements in the past few years. Most recently, the introduction of the MPEG-4 proposal has motivated a wide variety of approaches aimed al achieving a new level of video compression. In this paper we review progress in VLBV categorized into 3 main areas: (1) Waveform coding, (2) 2D content-based coding, and (3) Model-basedcoding. Where appropriate we also described proposals to the MPEG-4 committee in each of these areas.
In the general multiple video object coder, more interesting objects such as a speaker or a moving object is consistently coded with higher priority. Since the priority of each object may not be fixed in the whole seq...
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ISBN:
(纸本)0819450235
In the general multiple video object coder, more interesting objects such as a speaker or a moving object is consistently coded with higher priority. Since the priority of each object may not be fixed in the whole sequence and be variable on a frame by frame basis, it must be adjusted in a frame. In this paper, we analyze the independent rate control algorithm and the global algorithm that the QP value is controlled by static parameters, object importance or priority, the target PSNR and the weighted distortion. The priority among static parameters is analyzed and adjusted into dynamic parameters according to the visual interests or importance obtained by a camera interface. The target PSNR and the weighted distortion are proportional to magnitude, motion, and distortion. We apply these parameters for the weighted distortion control and the priority-based control leading to an efficient bit-rate distribution. As result, we have achieved that fewer bits are allocated for video objects which have less importance and more bits for those which have higher visual importance. The period to reach stability in the visual quality is reduced to less than 15 frames of the coded sequence. With respect to the PSNR, the proposed scheme shows higher quality of over 2dB than the conventional schemes. Thus the coding scheme interfaced to human-eyes proves to be an efficient video coder dealing with the multiple video objects.
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