# Talk:Elias omega coding

Who is Elias and why isn't that question addressed on this page? Michael Hardy 03:40, 23 Jan 2005 (UTC)

He's the guy that came up with these codes and it isn't addressed because no one has done it yet. -- Antaeus Feldspar 04:54, 23 Jan 2005 (UTC)
Maybe it's the mysterios P. Elias? see http://ieeexplore.ieee.org/xpl/abs_free.jsp?arNumber=1055349 . --Abdull 16:11, 9 March 2006 (UTC)
It's Peter Elias according to David Salomon's book "Variable-length Codes for Data Compression". I've added a link to Peter Elias for his delta, omega, and gamma codes. SteveJothen (talk) 19:44, 16 February 2009 (UTC)

## Implied probability

Classicalecon (talk · contribs) added "Implied probability" values to some of the entries of the table. I removed them because the article did not explain what "implied probability" was supposed to mean, and also because "implied probability" is not really accurate.

Ideally one picks a universal code to use so that a symbol which takes n bits to encode has a probability as close to 1/(n^2) as possible. This is not limited to this particular code; it's a basic fact of compression. If a symbol occurs 1/2 of the time, its optimal encoding is in 1 bit. If a symbol occurs 1/4 of the time, its optimal encoding is in 2 bits; if 1/8 of the time, in 3 bits; so on and so forth.

However, it's quite rare that one's probabilities would work out to exact powers of 2 like that. It's even rarer that all one's probabilities would work out to the exact powers of 2 that correspond to the specific powers of 2 that are optimal for a particular universal code. To say, therefore, that using a symbol of a particular bit length "implies" a particular probability is ... just grossly wrong.