基于SVD的无线多媒体传感器网络图像压缩机制

Image compression scheme in wireless multimedia sensor networks based on SVD

针对无线多媒体传感器网络图像压缩问题,从节点协作特性出发,提出了一种基于奇异值分解的图像压缩传输方案.首先研究了基于SVD的分块图像自适应压缩算法,以平衡网络能耗为目标,将相机节点和普通节点按照角色分工,协作完成图像采集、压缩和传输工作.相机节点负责采集图像信息,然后将图像分块发送给簇内普通节点;簇内普通节点对分块图像进行自适应压缩并将数据发送给簇头节点;簇头节点再将压缩后的数据转发至基站.仿真结果表明,提出的网络拓扑方案和图像压缩传输机制极大地缓解了图像采集节点的能耗压力,有效地平衡了网络的节点能耗.与JPEG2000协同图像压缩方案相比,基于SVD的图像处理方案的网络总能耗更少;且后者能够有效地对图像进行压缩传输,平衡网络能耗,延长整个网络的生命周期.

Aiming at the issue of image compression in wireless multimedia sensor networks, starting from the node collaboration features, an image compression and transmission scheme based on singu- lar value decomposition （SVD） is proposed. First, an adaptive blocking image compression algo- rithm based on SVD is studied. To balance the energy consumption of the network, according to the roles division, camera nodes and common nodes are cooperated to accomplish the workload of image acquisition, compression and transmission. Camera nodes gather images and send blocking images to the common nodes in cluster. Common nodes adaptively compress the partitioned images and send the compressed data to the cluster head node. Then, the cluster head node sends the compressed im- age data to the station. Simulation results show that the energy consumption pressure of camera nodes is greatly released by the proposed image compression and network topology scheme, and the network energy consumption is effectively balanced. Compared with the JPEG2000 collaborative im- age compression scheme, the total network energy consumption of the proposed cooperative image processing scheme based on SVD is less. In addition, the proposed scheme can effectively compress and transmit images, balance the energy consumption of network and prolong the life of the whole network.