DocumentCode :
2519437
Title :
Further results on relative redundancy
Author :
Das, Hirakendu ; Orlitsky, Alon ; Santhanam, Narayana P. ; Zhang, Junan
Author_Institution :
ECE, UCSD, La Jolla, CA
fYear :
2008
fDate :
6-11 July 2008
Firstpage :
1940
Lastpage :
1943
Abstract :
Standard redundancy measures the excess number of bits needed to compress a sequence as a function of the sequencepsilas length. Since long sequences can have arbitrarily low minimum description length (MDL), even low standard redundancy can be arbitarily high compared to the sequencepsilas MDL. By contrast, relative redundancy evaluates the excess number of bits as a function of the sequencepsilas MDL. Hence unlike standard redundancy, low relative redundancy implies that the number of bits needed to compress any sequence is essentially the lowest possible. Results in [1] show that for iid distributions over binary alphabets, block relative redundancy essentially equals block standard redundancy while sequential relative redundancy is about twice its standard counterpart. We show that unlike binary alphabets, for larger alphabets both block and sequential relative redundancy essentially equal their standard counterparts. We also define and determine expected relative redundancy and show that it is almost same as worst-case relative redundancy.
Keywords :
binary codes; binary sequences; block codes; sequential codes; binary alphabets; block relative redundancy; low minimum description length; sequence compression; sequential relative redundancy; standard redundancy; Compression algorithms; Length measurement; Measurement standards; Probability distribution;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Information Theory, 2008. ISIT 2008. IEEE International Symposium on
Conference_Location :
Toronto, ON
Print_ISBN :
978-1-4244-2256-2
Electronic_ISBN :
978-1-4244-2257-9
Type :
conf
DOI :
10.1109/ISIT.2008.4595327
Filename :
4595327
Link To Document :
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