This paper proposes the use of MAE-optimal Boolean and stack filters for sequential prediction in lossless grey-level image coding. FIR-Boolean hybrid filters are introduced as variations of Boolean filter structure a...
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ISBN:
(纸本)0818679204
This paper proposes the use of MAE-optimal Boolean and stack filters for sequential prediction in lossless grey-level image coding. FIR-Boolean hybrid filters are introduced as variations of Boolean filter structure and shown to be very effective for the prediction task. Different instances of optimal filtering are considered for realizing the prediction stage. First, the use of global-optimal predictors is analyzed, when the global MAE-optimal filter is used as a predictor. Then more refined structures, block-optimal and adaptive-size-block-optimal are considered, where predictors are adapted to local characteristics. These structures prove most suitable when small prediction masks are used. Extensive simulations are carried out for analyzing and comparing the performance of the newly introduced predictors and various other sequential predictors.
Verbmobil(1) is a speech-to-speech translation system for spontaneously spoken negotiation dialogs. The actual system translates 74.2% of spontaneously spoken German input. In the following we give an overview of the ...
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ISBN:
(纸本)0818679204
Verbmobil(1) is a speech-to-speech translation system for spontaneously spoken negotiation dialogs. The actual system translates 74.2% of spontaneously spoken German input. In the following we give an overview of the Verbmobil system. After the introduction of the Verbmobil scenario and the unique constraints of the project, we describe the underlying system architecture and its realization. The progress that was achieved on the end-to-end translation rate owes much to the increase of the word recognition rate from 45% in 1993 to 87% in 1996. But in order to achieve the envisaged coverage on the incertain speech recognizer output, deep and shallow approaches to the analysis and transfer problem had to be combined.
In many video coding schemes, especially at low bitrates, spatial and temporal subsampling of the image sequences is considered. This is realized by leaving out rows and columns from the images, and skipping whole fra...
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ISBN:
(纸本)0818679204
In many video coding schemes, especially at low bitrates, spatial and temporal subsampling of the image sequences is considered. This is realized by leaving out rows and columns from the images, and skipping whole frames at the transmitter. To get the best possible quality image sequence at the receiver side, the skipped portion of the video should be reconstructed using advanced motion-compensated (MC) postprocessing techniques. Our paper mainly focuses on the restoration / generation of unknown frames of the sequence at time instances, where the original scene has not been sampled, or which were skipped from the original sequence in the transmitter. This enhancement of the temporal resolution is performed using our advanced MC interpolation algorithm, utilizing an accelerated motion model and motion-based segmentation with proper handling of covered and uncovered areas. The algorithm can be used to avoid jerkiness and blurring of the restored image sequences.
We consider the problem of synthesizing feasible signals in the presence of inconsistent convex constraints, some of which are hard in the sense that they must absolutely be satisfied. This problem is formalized as th...
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ISBN:
(纸本)0818679204
We consider the problem of synthesizing feasible signals in the presence of inconsistent convex constraints, some of which are hard in the sense that they must absolutely be satisfied. This problem is formalized as that of minimizing an objective function measuring the degree of unfeasibility with respect to the soft constraints over the intersection of the sets associated with the hard constraints. We first investigate the process of aggregating soft constraints in order to define relevant objectives and then address the question of solving the resulting convex programs. Finally, we provide numerical results to illustrate the benefits of our analysis.
We presents results obtained by different contrast enhancement methods applied to medical images. We take into account classical histogram specification, local and wavelet-based techniques and a novel approach for mul...
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ISBN:
(纸本)0818679204
We presents results obtained by different contrast enhancement methods applied to medical images. We take into account classical histogram specification, local and wavelet-based techniques and a novel approach for multiscale contrast enhancement. The latter, whose rationale grounds in theories of visual perception, exploits a local definition of the Fechner-Weber's contrast within the-context of a non-linear scale-space representation generated by anisotropic diffusion. Our experimental fields concerns a difficult kind of medical images, namely digital mammographic images.
In this paper we report the results of an adaptive block-size transform coding scheme that is based on the sequential JPEG algorithm. This minimum information-overhead method implies a transform coding technique with ...
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ISBN:
(纸本)0818679204
In this paper we report the results of an adaptive block-size transform coding scheme that is based on the sequential JPEG algorithm. This minimum information-overhead method implies a transform coding technique with two different block sizes: N x N and 2N x 2N pixels. The input image is divided into blocks of 2N x 2N pixels and each of these blocks is classified according to its image activity. Depending on this classification, either four N-point or a single 2N-point 2-D DCT is applied on the block. The purpose of the algorithm is to take advantage of large uniform regions that can be coded as a single large unit instead of four small units - as it is made by a fixed block-size scheme. For the same reconstruction quality, the results of the adaptive algorithm show a significant improvement of the compression ratio with respect to the non-adaptive scheme.
The topic of this work, a joint scientific program merging the CEA, the IMAG, the CNES (France) and the Naval Research Laboratories (USA), is the evaluation of connectionist techniques for on-board signal and image pr...
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In the areas of image/speech processing, researchers have long dreamed of producing computer agents that can communicate with people in a human-like way. Although the non-verbal aspects of communications, such as emot...
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ISBN:
(纸本)0818679204
In the areas of image/speech processing, researchers have long dreamed of producing computer agents that can communicate with people in a human-like way. Although the non-verbal aspects of communications, such as emotions-based communications, play very important roles in our daily lives, most research so far has concentrated on the verbal aspects of communications and has neglected the nonverbal aspects. To achieve human-like agents we have adopted a two-way approach. 1. To provide agents with nonverbal communications capability, engineers have started research on emotions recognition and facial expressions recognition. 2. Artists have begun to design and generate the reactions and behaviors of agents, to fill the gap between real human behaviors and those of computer agents.
A new compression algorithm for fingerprint images is introduced. Using Lattice Vector Quantization (LVQ), a technique for determining the largest radius of the Lattice and its scaling factor is presented. The design ...
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ISBN:
(纸本)0818679204
A new compression algorithm for fingerprint images is introduced. Using Lattice Vector Quantization (LVQ), a technique for determining the largest radius of the Lattice and its scaling factor is presented. The design is based on obtaining the smallest possible Expected Total Distortion (ETD) measure, using a given bit budget, while using the smallest codebook size. In the proposed Piecewise-Uniform Pyramid LVQ, the wedge problem encountered with the Pyramidal Lattice point shells is resolved. At very low bit rates, for the coefficients with high-frequency content, the Positive-Negative Mean (PNM) method is proposed to improve the resolution of the reconstructed image. The proposed algorithm results in a high compression ratio and a high reconstructed image quality with a low computational load compared to other existing algorithms.
To transmit a video signal over the broadband networks, the first step is to compress the video stream in order to reduce the bit Tate. However, the lossy nature of the broadband networks will degrade the quality of l...
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ISBN:
(纸本)0818679204
To transmit a video signal over the broadband networks, the first step is to compress the video stream in order to reduce the bit Tate. However, the lossy nature of the broadband networks will degrade the quality of loss sensitive applications as compressed video signal. In this paper, a video subband coding system is discussed, which allows vs to compensate the information losses due to packed loss. This subband coding system treats the video over its three dimensions. one in time and two others in spatial. For the two spatial dimensions, the non-separable filter bank a's used which provides the better performances. A main principle idea in this coding system is that several channels with different priorities are offered. This novel scheme propose to transmit the video signal over the network with different levels of protection. So, even the packet loss occurs in the network, the most important part of information will be transmitted over a very protected channel and the rest of information which allows us just to increase the quality is sent over a normal channel. The simulation results prove the 3-D subband coding performance which is compared to the conventional coding system as MPEG in the same circumstances.
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