Compression d'images fixes et en stéréovision à faible complexité sur WSN

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Prolonging 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- fficient 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 omplexity and significant compatibility with the exact DCT. This transformation is applied to still image as well as stereo images. Simulation results clearly show that the proposed fast transform algorithm achieves a better trade-off between image quality, computational complexity and energy consumption compared to any existing pruned DCT approximations. urthermore, it is very suitable for the resource constrained wireless visual sensor networks (WVSNs) requiring low bitrates.