ZIDANI, Nesrine2024-07-302024-07-302024-06-27https://dspace.univ-annaba.dz//handle/123456789/3613Prolonging the lifetime of wireless sensor networks (WSN) is the biggest challenging issue. In wireless multimedia Sensor Networks (WMSNs), sensor nodes have limited energy resource and to increase the lifetime of the network, it is necessary to design an effective fast algorithm that aims at reducing the consumed power. In this thesis we proposed an energy-efficient discrete cosine transform (DCT) approximation requiring only 12 additions. Associated with a JPEG compression chain, this DCT approximation ensures a very good rate-distortion compromise, but above all, a very low computational complexity and significant compatibility with the exact DCT.enThesis