Talk:Coding theory

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Coding Theory generally refers to the two subjects Claude Shannon treated, Source (Compression) and Channel (error correcton). Cryptography is a different subject all together.

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I'm a bit of a neophyte here, but would it be proper to mention the sub-categories of coding theory as:

1) Compression coding 2) Coding for secrecy (cryptography) 3) error correction/detection 4) any others?

It sorta does, but its not explicit

Are compression and crypto part of coding theory? Maybe they are, but I think of coding theory as dealing with communications channels. Compression and crypto are independent of communications. Mirror Vax 08:27, 7 May 2005 (UTC)[reply]

Merge with "code" ?

Suggest this article should be merged with code. Both cover much the same territory, and both could use some beefing up.

This article goes into rather more detail, but that may be better devolved down to data compression and error correction.

-- Jheald 21:21, 5 March 2007 (UTC).[reply]

On second thoughts, maybe not. But then there needs to be some refactoring and clearer definition between the two. Jheald 22:39, 6 March 2007 (UTC)[reply]

Expand section tag

I have tagged the "source coding" section as could do with some expansion.

Source coding now redirects to data compression. Which I think is probably correct for the term overall; but requires that we need to make sure that material about the code-level aspects of source coding is still highlighted; and that this article takes up some of the slack too.

Relevant material that should be pointed to might include variable-length codes, prefix codes, Kraft inequality, Shannon's source coding theorem, ... more? -- Jheald 22:39, 6 March 2007 (UTC)[reply]

Expression: "minimize the entropy" right?

I wonder whether this is the right expression:

Quote: "Data compression which explicitly tries to minimise the entropy of messages according to a particular probability model is called entropy encoding."

Isn't "entropy" the amount of disorder or randomness in information? So once compressed, the disorder will rather be maximized and not minimized. AAAAAA has little disorder, is thus little compressed and, to my opinion, exhibits a low entropy.

-- User:haensel 11:57, 9 May 2008 (UTC)[reply]

Citation not needed

There are a lot of "citation needed" tags on this webpage. I don't really see the need for all of them. Mathematical facts are usually not given any citation on wikipedia as anyone can check by reading other mathematical articles. This is a sensible policy since they are not likely to be controversial.

Some of the claims with the "citation needed" tag definitely fall in this category. Like the claim that no code can do better than the entropy of the source. Anyone who has taken a introductory information theory course will likely have seen the proof of that claim. —Preceding unsigned comment added by 90.229.231.115 (talk) 20:41, 6 August 2008 (UTC)[reply]

Reference

Removing my addition in references "F. J. MacWilliams, N. J. A. Sloane, The Theory of Error-Correcting Codes" is bad idea since 5 years ago I work in Codding Theory and know, that this is fundamental book. Now I am not so interesting in Codding Theory, and so I not plan to add this reference in correct standard. I note this, if somebody want to do this.Vavlap (talk) 10:52, 23 July 2008 (UTC)[reply]

The problem isn't with the book, or with how you wrote it to the references section. The only problem is only that you did not *also* use the book in the article. For instance:

In particular, no source coding scheme can be better than the entropy of the source.

currently needs a citation to a reliable source, such as MacWilliams and Sloane. Find out where that book says this is true, and add the page number. If it was on page 50, it would be fine to say:

In particular, no source coding scheme can be better than the entropy of the source (MacWilliams & Sloane, p. 50).

Someone else will add the fancy wiki syntax. JackSchmidt (talk) 14:24, 23 July 2008 (UTC)[reply]