Image compression techniques in the field of security technology: examples and discussion

The image compression techniques are widely applied in the field of security technology (perimeter supervision, CCTV in facilities, faces, fingerprints, car plates etc.). The extensive and dramatically expanding use of image information requires increasing capacity of either transmission channels or retrieving devices. The image compression techniques offer a partial solution of this problem but there are some shortcomings to be avoided. During last years, we have tested and evaluated a set of different image compression techniques from the security point of view in a relation to a standard visual quality evaluation. The results have been part-by-part presented at several previous Carnahan conferences (Lucas and Kanade, 2001; Swain and Ballard,1991; Comanaciu, 2003). The paper presents summarized information about these results and based upon them a comprehensive discussion and conclusions are derived. Moreover some new results related to the VQ (vector quantization) and video coding are presented too.