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Proceedings Paper

Low Bit Rate Television On ISDN
Author(s): Hamid Gharavi
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Paper Abstract

This paper discusses a hybrid coding method for low bit-rate video transmission over the 2B channels (128 kb/s) of ISDN networks. In this method the coding frame is divided into two dimensional m-by-m blocks where each block is further divided into smaller sub-blocks. Block classification and blockmatching motion estimation are based on the larger block size, while the transformation is performed on a sub-block basis. The transform coefficients are coded in such a way that the inter sub-block correlation can be efficiently exploited. As a result, for every block the sub-block coefficients are scanned by grouping all the first coefficients, followed by all the second coefficients and so on. The manner in which the sub-blocks are scanned is called inter sub-block scanning. Three types of sub-block scanning are considered: zig-zag, horizontal and vertical scanning. The inter sub-block scanning is made adaptive by deciding which of the above scanning types is the most efficient. Consequently, this requires additional overhead to be sent to the receiver at the beginning of each block. In our simulation the main block size of 16 x 16 and 32 x 32 is considered. In order to find the best sub-block size, four different sizes such as 2 x 2, 4 x 4, 8 x 8 and 16 x 16 are evaluated. The results using a few video sequences as the input show that a good quality video can be obtained at the transmission rates of 48 kb/s, 64 kb/s and 112 kb/s.

Paper Details

Date Published: 5 April 1989
PDF: 8 pages
Proc. SPIE 1075, Digital Image Processing Applications, (5 April 1989); doi: 10.1117/12.952641
Show Author Affiliations
Hamid Gharavi, Bellcore (United States)


Published in SPIE Proceedings Vol. 1075:
Digital Image Processing Applications
Ying-Wei Lin; Ram Srinivasan, Editor(s)

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