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2. VIDEO COMPRESSION |
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Importance of video compression has led researches to be focused in the area of video compression and developed a number of succeeded compression algorithms. One of the most known algorithms is H.263 [1] standard. It is DCT based and uses a motion-compensated technique to discard same or correlated frames. Compared to MPEG-1 and MPEG-2 standards, it gives better quality in less bit rates. H.263 standard has not been developed for low bit rates but also high resolution, full quality video streams for high bit rates. Another technique is scalable video coding. This technique is developed for pure computational decoding and limited transmission bandwidths and can be decoded in variety bit rates. MPEG-2 standard contains basic mechanisms of this technique. Besides ITU-R 601-4 standard is the first technique developed specifically for this purpose. It supports bit rates ranging from 64 Kbit/s to 4 Mbit/s. Region based motion compensation (MC) technique is today’s most known coders’ fundamental element. MPEG-4[2] standard uses this technique integrated with wavelet transform and an efficient quantization algorithm.
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