We suggest an optimization-based method for halftoning that involves looking ahead before a decision for each binary output pixel is made. We first define a mixture distortion criterion that is a combination of a freq...
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We suggest an optimization-based method for halftoning that involves looking ahead before a decision for each binary output pixel is made. We first define a mixture distortion criterion that is a combination of a frequency-weighted mean square error (MSE) and a measure depending on the distances between minority pixels in the halftone, A tree-coding approach with the ML-algorithm is used for minimizing the distortion criterion to generate a halftone. While this approach generates halftones of high quality, these halftones are not very amenable to lossless compression. We introduce an entropy constraint into the cost function of the tree-coding algorithm that optimally trades off between image quality and compression performance in the output halftones.
We study a new speech coding architecture based on the concept of tree coding along with recursive least squares lattice short term prediction and gradient/autocorrelation based long term prediction algorithms that ad...
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ISBN:
(纸本)9780738131269
We study a new speech coding architecture based on the concept of tree coding along with recursive least squares lattice short term prediction and gradient/autocorrelation based long term prediction algorithms that adapt on the reconstructed output values of the codec, thus substantially reducing the number of parameters to be quantized, coded, and transmitted. The codec uses a perceptually weighted distortion measure similar to the popular analysis-by-synthesis codecs widely deployed today, but the codec differs from current codecs in that the codec is a sliding block analysis-by-synthesis scheme that is nearer waveform coding, which should allow smoother tracking of transitions and the reduction of block based artifacts. Voice activity detection (VAD) and comfort noise generation (CNG) are added to reduce the bit rate and the number of computations required. We present performance comparisons with G.711 using the same VAD/CNG and investigate the performance of a standard long (pitch)/short term predictor structure with a 10th order autoregressive predictor. It is shown that a bit rate reduction of 70 per cent can be achieved while maintaining nearly perceptually equivalent speech quality.
In general, growth algorithms for optimal tree-structured vector quantizers do not exist. In this paper we show that if the source satisfies certain conditions;namely, that of diminishing marginal returns;optimal grow...
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In general, growth algorithms for optimal tree-structured vector quantizers do not exist. In this paper we show that if the source satisfies certain conditions;namely, that of diminishing marginal returns;optimal growth algorithms do exist. We present such an algorithm and compare its performance with that of other tree growth algorithms. Even for sources that do not meet the necessary conditions for the growth algorithm to be optimal, such as for speech with unknown statistics, it is seen by simulation that the algorithm outperforms other known growth algorithms. For sources that do not satisfy the required conditions, the algorithm presented here can also be used to grow the initial tree for the pruning process. The performance of Such pruned trees is superior to that of trees pruned from full trees of the same rate.
Data fitting is the process of constructing a curve, or a set of mathematical functions, that has the best fit to a series of data points. Different with constructing a fitting model from same type of function, such a...
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Data fitting is the process of constructing a curve, or a set of mathematical functions, that has the best fit to a series of data points. Different with constructing a fitting model from same type of function, such as the polynomial model, we notice that a hybrid fitting model with multiple types of function may have a better fitting result. Moreover, this also shows better interpretability. However, a perfect smooth hybrid fitting model depends on a reasonable combination of multiple functions and a set of effective parameters. That is a high-dimensional multi-objective optimization problem. This paper proposes a novel data fitting model construction approach. In this approach, the model is expressed by an improved tree coding expression and constructed through an evolution search process driven by the genetic programming. In order to verify the validity of generated hybrid fitting model, 6 prediction problems are chosen for experiment studies. The experimental results show that the proposed method is superior to 7 typical methods in terms of the prediction accuracy and interpretability.
Using well-known results from statistical physics, concerning the almost-sure behavior of the free energy of directed polymers in a random medium, we prove that random tree codes achieve the distortion-rate function, ...
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Using well-known results from statistical physics, concerning the almost-sure behavior of the free energy of directed polymers in a random medium, we prove that random tree codes achieve the distortion-rate function, not only on the average, but moreover, almost surely under a certain symmetry condition.
The use of the generalized Breiman, Friedman, Olshen, and Stone (BFOS) algorithm, a recently developed technique for variable rate vector quantizer design, for optimal bit allocation is analyzed. It is shown that if e...
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The use of the generalized Breiman, Friedman, Olshen, and Stone (BFOS) algorithm, a recently developed technique for variable rate vector quantizer design, for optimal bit allocation is analyzed. It is shown that if each source has a convex quantizer function, then the complexity of the algorithm is low.
tree structures make an appearance in many network related problems, such as network routing. Modelling and simulating the appearance of these data structures can be done using random tree generators. However, there h...
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ISBN:
(纸本)9798350395389
tree structures make an appearance in many network related problems, such as network routing. Modelling and simulating the appearance of these data structures can be done using random tree generators. However, there has been very little study on random models that are able to capture the dynamics of networks. We introduce the random spanning tree model, which is a random tree generator that is based on generating a tree from an already existing network topology. The Shannon entropy of this model is then analysed, and upper bounds to it are found. As compression can be beneficial because of the complexity of large trees, we then introduce a universal approach to compressing trees generated using the spanning tree model. It will be shown that the proposed method of compression introduces a redundancy that tends to zero for larger trees. We recommend the use of this random model and the proposed compression algorithm in routing protocols of IoT, as it can contribute to saving routing communication overhead and increasing the overall lifetime of the network.
Routing tables in ad hoc and wireless routing protocols can be represented using rooted trees. The constant need for communication and storage of these trees in routing protocols demands an efficient rooted tree codin...
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ISBN:
(纸本)9781665454681
Routing tables in ad hoc and wireless routing protocols can be represented using rooted trees. The constant need for communication and storage of these trees in routing protocols demands an efficient rooted tree coding algorithm. This efficiency is defined in terms of the average code length, and the optimality of the algorithm is measured by comparing the average code length with the entropy of the source. In this work, treeExplorer is introduced as an easy-to-implement and nearly optimal algorithm for coding rooted tree structures. This method utilizes the number of leaves of the tree as an indicator for choosing the best method of coding. We show how treeExplorer can improve existing routing protocols for ad hoc and wireless systems, which normally entails a significant communication overhead.
The square parts layout is the most used solution in the current manufacturing industry. The target product is cut through the order layout, and then production is completed after product classification. However, ther...
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ISBN:
(纸本)9781665463539
The square parts layout is the most used solution in the current manufacturing industry. The target product is cut through the order layout, and then production is completed after product classification. However, there is a huge contradiction between the production efficiency and personalized production of the current order. In order to increase the production rate and maximize the utilization rate of raw material, the other party layout is required to be carefully optimized to make the production process more fine standards, reduce waste of resources and energy enterprises, to maximize benefits under the premise of meeting orders. For sampling optimization issues, give the best cutting solution, establish a mixed integer planning model, and make reasonable sampling of product items. On the basis of meeting the constraints, the use of board can maximize the utilization rate. Innovatively use the genetic algorithm of tree codes to solve it, and use the tree-like gene encoding to convert into a string gene encoding to obtain the use rate of each data set. In summary, the use of tree coding genetic algorithms to solve the problem to make the cutting of the board more reasonable. At the same time, optimize the order layout plan, speed up the production progress, maximize the benefits, and the waste of resources is reduced on the premise of meeting the order requirements, so as to bring practical benefits to the industrial production of enterprises.
In this paper, a high quality, and in many prospects, efficient, wavelet color image codec (WCIC) is introduced. This codec allows to achieve high compression ratios with little degradation in visual quality. WCIC sim...
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ISBN:
(纸本)0819422355
In this paper, a high quality, and in many prospects, efficient, wavelet color image codec (WCIC) is introduced. This codec allows to achieve high compression ratios with little degradation in visual quality. WCIC simultaneously exploits several characteristics of the wavelet transforms (multiresolution decompositions). Wavelet transform is formed using wavelet packets via lattice structures. Bit allocation algorithm is developed to distribute the bits between and in the colors such that minimal mean-squared-error (MSE) is introduced in each color component. This proves to be beneficial at low bit rates which keeps the color distribution in balance. The wavelet coefficients are quantized using either trellis or zero-tree quantizers depending on their statistics. Quantized coefficients are further compressed with adaptive arithmetic coding resulting in the final coded bit stream. This codec is applied to a wide range of images, from computer animations to natural pictures. The results are compared to other algorithms, including fractals and JPEG, and relative merits of the proposed algorithm are presented.
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