A fundamental goal of digital image compression is to reduce the bit rate for transmission or data storage while maintaining an acceptable fidelity or image quality. In this study a proposed coding (compression) schem...
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A fundamental goal of digital image compression is to reduce the bit rate for transmission or data storage while maintaining an acceptable fidelity or image quality. In this study a proposed coding (compression) scheme for grey scale image by combining discrete wavelet transform (DWT), multistage vector quantization (MSVQ) and Huffman coding is presented. These combinations are utilized to take the advantages provided by all of them to get high compression ratio with acceptable recovered image quality in term of Peak Signal to Noise Ratio (PSNR) instead of using each method separately. First, the discrete wavelet transform is performed on the original image using bi-orthogonal 9/7 filter (bior4.4) resulting in number of sub-bands according to the decomposition level that can be one, two or three in the proposed scheme. Huffman coding applied on the approximation sub-band, and on the indices of the last level detail sub-bands that are vector quantized by two stages using LBG algorithm which forms the basis of most vector quantizer designs, other detail sub-bands set to zero if the decomposition level is greater than one to increase the compression ratio.
With the advent of mobile devices, the internet now undertook a huge and unexpected explosion of growth. The wireless mobile internet gives users access to the internet services while they are on the move. This mobili...
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With the advent of mobile devices, the internet now undertook a huge and unexpected explosion of growth. The wireless mobile internet gives users access to the internet services while they are on the move. This mobility has been supported through the Internet Protocol known as Mobile IP. Mobile IP allows users with mobile devices to have continuous network connectivity to the internet without changing their IP addresses when moving from one network to another. While on move, the Mobile Node (MN) undergoes a handover process, in which the MN gets disconnected from one network and tries to connect to another network, i.e., New Access Router (NAR). The handover process involves various time-consuming procedures as Neighbor Discovery, Care-of-Address (CoA) configuration, Duplicate-Address-Detection (DAD), Binding Registration and Route Optimization. Various researches have been devoted to the acceleration of movement detection and registration. However, a time-consuming operation, i.e., duplicate-address detection (DAD), was overlooked by most studies. An improved architecture for minimizing the handover latency in MIPv6 is improved in this paper. The improved architecture suggests the removal of DAD procedure and configuration of a new CoA for the MN by the NAR. The result is evaluated on the basis of numerical analysis.
Cloud computing is an emerging computing paradigm in which IT resources and capacities are provided as services over the Internet. Promising as it is, this paradigm also brings forth new challenges for data security a...
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