Improved vector quantization scheme for grayscale image compression

This paper proposes an improved image coding scheme based on vector quantization. It is well known that the image quality of a VQ-compressed image is poor when a small-sized codebook is used. In order to solve this problem, the mean value of the image block is taken as an alternative block encoding rule to improve the image quality in the proposed scheme. To cut down the storage cost of compressed codes, a two-stage lossless coding approach including the linear prediction technique and the Huffman coding technique is employed in the proposed scheme. The results show that the proposed scheme achieves better image qualities than vector quantization while keeping low bit rates.     

Variable-rate colour image quantization based on quadtree segmentation

A novel variable-sized block encoding with threshold control for colour image quantization (CIQ) is presented in this paper. In CIQ, the colour palette used has a great influence on the reconstructed image quality. Typically, a higher image quality and a larger storage cost are obtained when a larger-sized palette is used in CIQ. To cut down the storage cost while preserving quality of the reconstructed images, the threshold control policy for quadtree segmentation is used in this paper. Experimental results show that the proposed method adaptively provides desired bit rates while having better image qualities comparing to CIQ with the usage of multiple palettes of different sizes.     

On a dynamical quantization

A concept of a noncanonical quantization, called dynamical quantization, is defined in an axiomatic way. A dynamical quantization of a system of two nonrelativistic point particles interacting via a harmonic potential is considered in more details. The quantized system exhibits some new features. In particular, it has finite space dimensions. The distance between the particles is preserved in time and can have at most four different values. The position of any one of them cannot be localized, since the operators of the coordinates do not commute. The particles are smeared with a certain probability within a finite volume, which moves together with their centre of mass. The orbital momentum of the composite system is either one or zero.Presented at the International Symposium Selected Topics in Quantum Field Theory and Mathematical Physics, Bechyn, Czechoslovakia, June 14–19, 1981.     

A quantization scheme for scale-invariant pure gauge theories

A scheme is suggested for the quantization of the recently proposed scale-invariant gauge theories in higher dimensions. The model is minimally coupled to a spinor field. Regularization algorithms are proposed.     

Chiral anomalies in the stochastic quantization scheme

Stochastic quantization scheme with an invariant stochastic regularization is applied to models of chiral fermions in even-dimensional spacetime. In spite of the manifest preservation of chiral gauge symmetries by stochastic regularization of the stochastic averages, the anomalous chiral Ward identities are correctly reproduced in a covariant form after removing the regularization.This Letter covers part of the content of the preprint [11].Address since 15 December, 1985: CERN, Theory Division, CH-1211 Geneva 23, Switzerland.     

Different representations of R-function and parameterized quantization scheme

Three different representations of R-function distribution are deduced for a given density operator of light field in terms of Q-function, Wigner function and positive P-representation, respectively. Furthermore, the τ-parameterized quantization scheme is proposed, where the P-representation, Weyl correspondence, and Q-function are as its special cases. As applications, the photon-count distribution from R-function and the nonclassical depth of photon-added coherent state are examined.     

Rate-oriented perceptual image coding using contrast-based quantization

<正>A new image coding approach is proposed by controlling the quantization step via minimizing the perceptual distortions(in terms of image's contrast measurement).The proposed method is a rate-oriented contrast-based approach,which is in contrast to the conventional quality-oriented contrast-based image coding.The algorithm achieves a higher perceptual quality performance against several methods developed previously.     

A hybrid quantum encoding algorithm of vector quantization for image compression

Many classical encoding algorithms of vector quantization (VQ) of image compression that can obtain global optimal solution have computational complexity O(N). A pure quantum VQ encoding algorithm with probability of success near 100% has been proposed, that performs operations 45\sqrt{N} times approximately. In this paper, a hybrid quantum VQ encoding algorithm between the classical method and the quantum algorithm is presented. The number of its operations is less than \sqrt{N} for most images, and it is more efficient than the pure quantum algorithm.     

一种基于图像融合的运动目标快速检测算法

提出了一种新的运动目标检测方法,这种方法可以有效的提取目标轮廓。应用一种图像差分技术得到运动目标的初始轮廓线。使用了动态轮廓线使其收敛到目标轮廓。提出了一种新的目标轮廓特征级融合方法,求解两类模式图像的收敛动态轮廓线控制点向量差的范数平方极小化。这种方法不需要图像配准降低了融合的计算复杂度,有效提高了可见光图像中目标轮廓提取的精度。对比检测实验证实了算法的有效性。设计了一种基于Newmark方法的动态轮廓线快速迭代算法,将该方法和方法作了比较,对比实验表明这种方法的时间复杂度降低了22%。     

On Dirac's quantization condition

The consequences of Dirac's quantization condition are discussed. Observing that this condition generally leads to contradiction and that the normal explanation to resolve the contradiction seems unsatisfactory, we propose a modified quantization condition. It is shown that operator ordering ambiguity could be represented as the arbitrariness of the distribution functions in the modified condition.     

二维彩色彩虹像面全息图记录的一种新方法

本文提出了利用液晶光阀和单色激光进行彩色全息图记录的方法.借助于液晶光阀非相干-相干转换的功能,采用新的彩虹全息术,获得了记录于同一块干版上的原彩色目标由红、绿、篮三色所成的三个基色彩虹全息像.用白光透射再现,得到原彩色图的真彩色全息像.这种方法是液晶光阀、条形散斑屏在图像处理中的一种特殊应用.     

On quantization of r matrices for Belavin-Drinfeld triples

We suggest a formula for quantum universal R matrices corresponding to quasitriangular classical r matrices classified by Belavin and Drinfeld for all simple Lie algebras. The R matrices are obtained by twisting the standard universal R matrix.     

基于小波变换和矢量量化的语音压缩编码方案

对于一种新的语音压缩编码方法——基于小波变换和矢量量化的语音压缩编码方案进行了开发和研究。该方法先对语音进行小波变换和小波包变换,然后使用矢量量化来压缩数据.我们还研究了使用摘编码方法进一步降低比特率的算法,实验结果表明对于采样频率为8kHz,每样本量化为8bit的64kbit/s语音信号压缩到6kbit/s~8kbit/s时,具有良好的语音质量.同时该算法还具有低延迟的优点,其算法延迟只有8ms。     

s-parameterized Weyl transformation and the corresponding quantization scheme

By extending the usual Weyl transformation to the s-parameterized Weyl transformation with s being a real parameter,we obtain the s-parameterized quantization scheme which includes P–Q quantization,Q–P quantization,and Weyl ordering as its three special cases.Some operator identities can be derived directly by virtue of the s-parameterized quantization scheme.     

Efficient greyscale image compression technique based on vector quantization

In this paper, a novel greyscale image coding technique based on vector quantization (VQ) is proposed. In VQ, the reconstructed image quality is restricted by the codebook used in the image encoding/decoding procedures. To provide a better image quality using a fixed-sized codebook, the codebook expansion technique is introduced in the proposed technique. In addition, the block prediction technique and the relatively address technique are employed to cut down the required storage cost of the compressed codes. From the results, it is shown that the proposed technique adaptively provides better image quality at low bit rates than VQ.     

On the quantization of gravity

We analyse the construction of quantum states for the case of gravity and matter using the solution of the 2-submanifold boundary value problem and “sum over paths” quantisation. This leads to a specification of such states in terms of a complete commuting set of operators. The “sum over topologies” definition is obtained only by a very ad hoc assumption which is made precise. The problem of the arbitrariness of the background metric discussed and resolved by analogy with QED.