No / As existing video processing technology is primarily
developed in the pixel domain yet digital video is stored in compressed
format, any application of those techniques to compressed
videos would require decompression. For discrete cosine transform
(DCT)-based MPEG compressed videos, the computing cost of
standard row-by-row and column-by-column inverse DCT (IDCT)
transforms for a block of 8 8 elements requires 4096 multiplications
and 4032 additions, although practical implementation only
requires 1024 multiplications and 896 additions. In this paper, we
propose a new algorithm to extract videos directly from MPEG
compressed domain (DCT domain) without full IDCT, which is
described in three extraction schemes: 1) video extraction in 2 2
blocks with four coefficients; 2) video extraction in 4 4 blocks
with four DCT coefficients; and 3) video extraction in 4 4 blocks
with nine DCT coefficients. The computing cost incurred only
requires 8 additions and no multiplication for the first scheme,
2 multiplication and 28 additions for the second scheme, and
47 additions (no multiplication) for the third scheme. Extensive
experiments were carried out, and the results reveal that: 1) the
extracted video maintains competitive quality in terms of visual
perception and inspection and 2) the extracted videos preserve the
content well in comparison with those fully decompressed ones
in terms of histogram measurement. As a result, the proposed
algorithm will provide useful tools in bridging the gap between
pixel domain and compressed domain to facilitate content analysis
with low latency and high efficiency such as those applications in
surveillance videos, interactive multimedia, and image processing.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/2785 |
| Date | 09 June 2009 |
| Creators | Jiang, Jianmin, Weng, Y. |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, No full-text available in the repository |
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