In existing interframe predictive coding schemes, prediction error is minimized when the prediction factor is the same as the interframe correlation; methods based on complete prediction (with a prediction factor of 1...
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作者：
Sikora, TLaboratory of Chromatography
DEPg.Fac.Quimica Universidad Nacional Autonoma de Mexico Circuito interior Cd Universitaria/CP 04510 Mexico D.F.Mexico
A design approach is presented which allows the optimization of coefficients for symmetric and separable finite impulse response (FIR) interpolation filters for multiresolution coding schemes, The interpolation filter...
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A design approach is presented which allows the optimization of coefficients for symmetric and separable finite impulse response (FIR) interpolation filters for multiresolution coding schemes, The interpolation filters serve as optimal inverse filters in the Wiener sense and are designed to match the characteristics of the specific filters used for decimation as well as for the statistics of ''typical'' images to be reconstructed, Applied to the coding of test images in a four-level progressive pyramid scheme, the optimal interpolation filters generated substantially improved rate-distortion results compared to conventional filters.
In this paper we propose a segmentation structure to generate a partition tree with multiple partition proposals. These multiple partitions are obtained for every image in a hierarchical way, front the coarsest one to...
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In this paper we propose a segmentation structure to generate a partition tree with multiple partition proposals. These multiple partitions are obtained for every image in a hierarchical way, front the coarsest one to the finest one, Time evolution of the regions is defined through a projection step which relates the previous coded partition with the current partition tree, Finer partitions than the projected one are defined segmenting the projected partition using texture criteria, while coarser partitions are obtained merging regions with motion criteria. Morphological tools are used both in the projection and the re-segmentation steps.
In existing interframe predictive coding schemes, prediction error is minimized when the prediction factor is the same as the interframe correlation;methods based on complete prediction (with a prediction factor of 1)...
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In existing interframe predictive coding schemes, prediction error is minimized when the prediction factor is the same as the interframe correlation;methods based on complete prediction (with a prediction factor of 1) thus do not achieve optimum prediction. Interframe leaky prediction was used in art effort to solve this problem. In the leaky prediction method proposed here, the frame type is determined from the interframe correlation and the leaky prediction coefficient, resulting in more efficient interframe ceding. Complete prediction is used for nonsignificant blocks, preventing the number of significant blocks from increasing. To eliminate errors, intraframe cyclic refresh was combined with leaky prediction, thus improving recovery of image quality. The new method is well suited to moving image coding in ATM systems. Software simulations demonstrate that the method is effective.
Transmission of compressed video over packet networks with nonreliable transport benefits when packet loss resilience is incorporated into the video coding, One promising approach to packet loss resilience, particular...
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Transmission of compressed video over packet networks with nonreliable transport benefits when packet loss resilience is incorporated into the video coding, One promising approach to packet loss resilience, particularly for transmission over networks offering dual priorities such as asynchronous transfer mode (ATM) networks, is based on layered coding which uses at least two bitstreams to encode video, The base-layer bitstream, which can be decoded independently to produce a lower quality picture, is transmitted over a high priority channel, The enhancement-layer bitstream(s) contain less important information, so that packet losses are more easily tolerated, The MPEG-2 International Standard provides four methods to produce a layered video bitstream: data partitioning, signal-to-noise ratio scalability, spatial scalability, and temporal scalability, Each of these techniques was included in the standard in part for motivations other than loss resilience, This paper compares the performance of these techniques (excluding temporal scalability) under various loss rates using realistic length video material and discusses their relative merits taking implementation issues into consideration. Nonlayered MPEG-2 coding gives generally unacceptable video quality for packet loss ratios of 10(-3) for small (single ATM cell) packet sizes, Better performance can be obtained using layered coding and dual-priority transmission, With data partitioning, the simplest to implement among the three, cell loss ratios of 10(-4) in the low-priority layer are definitely acceptable, while for SNR scalable encoding, cell loss ratios of 10(-3) are generally invisible, even to experienced viewers, Spatial scalable encoding can provide even better visual quality under packet losses;however, it has a high implementation complexity.
In this paper, we present JPEG-based scalable image compression algorithms for storage and transmission applications. The JPEG standard for still image compression provides the framework for reconstructing images in d...
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In this paper, we present JPEG-based scalable image compression algorithms for storage and transmission applications. The JPEG standard for still image compression provides the framework for reconstructing images in different sizes and picture qualities. These features are generally referred to as spatial and SNR scalability, respectively, and are extremely important in a variety of applications. A review of the different modes of the JPEG standard followed by the implementation and performance evaluation of the progressive and hierarchical coding modes which provide SNR and spatial scalability, respectively, are detailed. We then present a highperformance technique based on Wavelet filter downsampling for achieving spatial scalability within the framework of the hierarchical mode of the JPEG standard. This technique provides substantial improvement in performance while maintaining the compatibility with existing JPEG decoders.
Intending to contribute to constructing better multimedia network systems, we propose a new concept of image database system of which form of storage is featuring exponential or graceful oblivion and abrupt recollecti...
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Intending to contribute to constructing better multimedia network systems, we propose a new concept of image database system of which form of storage is featuring exponential or graceful oblivion and abrupt recollection like the human memory property. By virtue of this property of database storages that is realized by employing hierarchical or pyramidal image coding, the database memory and transmission costs can be significantly reduced. In this paper we will describe the details of the concept, the results of theoretical analysis based on a simplified model which reveals the effectiveness of the proposed system, the structure of an experimental prototype system and the result of an experimental image retrieval service carried out by implementing it over ATM high speed channels.
A highly effective video coding method is proposed for application in a wide range of fields that utilize video information and in multimedia systems where data must be easily manipulated. The proposed video coding sc...
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A highly effective video coding method is proposed for application in a wide range of fields that utilize video information and in multimedia systems where data must be easily manipulated. The proposed video coding scheme is a hierarchical system that uses vector quantization and which also incorporates many of the basic coding components of the internationally standardized low-rate MPEG 1 coding system. In addition to providing the special data handling operations of MPEG 1, the new system incorporates a multiresolution hierarchical decomposition that permits the user to select a desired resolution level at the decoder. Source coding is achieved with mean-separated normalized vector quantization applied to image blocks that contain fundamental image patterns. However, instead of using separate codebooks for each of the different prediction modes of the coding system, this paper shows that it is possible for various prediction modes to share codebooks to achieve a more efficient implementation. The coding efficiency of the new system is estimated and compared with the performance of a DCT based system. Although the signal-to-noise ratio of the VQ system falls short by 0.5 to 1.2 dB, subjectively, the two coding systems give about the same performance. Methods for improving the quantitative signal-to-noise ratio performance are also considered.
In this paper, functional requirements for the MPEG 2 coding method are presented and, as an implementation method of these requirements, a hierarchical video coding scheme is proposed. in the proposed coding method, ...
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In this paper, functional requirements for the MPEG 2 coding method are presented and, as an implementation method of these requirements, a hierarchical video coding scheme is proposed. in the proposed coding method, the prediction efficiency is increased by introducing spatial prediction in addition to temporal prediction as used in the MPEG 1 coding method. The hierarchical scheme is also characterized by the following features. (1) The input format is an output device-independent noninterlaced video;(2) the coder has a hierarchical structure that permits the resolution level to be selected by the user;(3) by means of a small number of operations and a wide compensation area, the coder gives a motion-detection method which detects motion vectors of each layer and a coding method of motion vectors;and (4) the proposed coding system introduces the use of down/up sampling processes with no phase distortion. Furthermore, the coding data description method is realized as an extension of that used by MPEG 1 and thus retains the compatibility. Simulation experiments show that this coding method satisfies the functional requirements without any obvious decrease in coding efficiency.
作者：
HUANG, LBIJAOUI, AObservatoire
de la Côte d'Azur. Dep. A. Fresnel. URA 1361 CNRS. B.P. 139 F-06003 Nice Cedex France
We present in this paper an efficient image compression algorithm without distortion. It is based on a special iterative central prediction method with a hierarchic 4-bit code. By applying this method to some hydrodyn...
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We present in this paper an efficient image compression algorithm without distortion. It is based on a special iterative central prediction method with a hierarchic 4-bit code. By applying this method to some hydrodynamic simulation images, high compression ratios have been obtained.
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