this paper presents a new coding method for image compression based on jpeg2000 and contourlet transform. jpeg2000 standard is a common standard that uses discrete wavelet transform (dwt) in the compression process. the main problems of dwt are failure to detect curved edges in image and its shortage representation of the ridge and furrow patterns which cause deficiency and block artifacts rema...

In parametric speech coding, the accuracy of parameter quantization has a significant effect on speech quality. In this paper, we present a flexible and high-fidelity multi-mode quantization approach that combines the beneficial features of predictive vector quantization and matrix quantization. As an example, the proposed technique is employed in quantization of the power component in a wavefo...

In this paper we compare light-front quantization and instant-time both at the level of operators their Feynman diagram matrix elements. At lead to equal time commutation (or anticommutation) relations that appear be quite different from relations. Despite show unequal times actually can transformed into each other, with it only being restriction makes so different. While our results are valid ...