Maximizing image quality over Visual Sensor Networks via DCT bit allocation

Recently, VSNs (Visual Sensor Networks) are becoming of increased interest in a variety of applications. Due to power constraints at each visual sensor node, the processing of live video is constrained. In this paper, we propose a DCT (Discrete Cosine Transform)-based bit allocation scheme to maximize image quality for a given bit rate constraint. Two major featured algorithms are proposed : “SLO” (Searching from the Lowest Order) and “SPP” (Searching the Present optimal bit allocation from the Previous optimal bit allocation). The proposed algorithms reduce the search range based on a simple IQA (Image Quality Assessment) model and DCT statistics. Thus, they demonstrate low-complexity and fast computation. In the simulations, we show the superiority of the proposed algorithms over conventional approaches.

[1]  Eero P. Simoncelli,et al.  Image quality assessment: from error visibility to structural similarity , 2004, IEEE Transactions on Image Processing.

[2]  Michael W. Marcellin,et al.  A method for coordinating the distributed transmission of imagery , 2006, IEEE Transactions on Image Processing.

[3]  Robert W. Heath,et al.  Rate Bounds on SSIM Index of Quantized Images , 2008, IEEE Transactions on Image Processing.

[4]  K. Ramchandran,et al.  Distributed video coding in wireless sensor networks , 2006, IEEE Signal Processing Magazine.

[5]  Ian F. Akyildiz,et al.  A survey on wireless multimedia sensor networks , 2007, Comput. Networks.

[6]  Prashant J. Shenoy,et al.  SensEye: a multi-tier camera sensor network , 2005, ACM Multimedia.