Lossless Compression Handbook

CHAPTER 5 / ARITHMETIC CODING 103

Second, many of the patents have expired (e.g., [11, 16]), or became obsolete. Finally, we do

not need to worry so much about complexity-reduction details that obscure the inherent simplic-

ity of the method. Current computational resources allow us to implement simple, efficient, and

royalty-free arithmetic coding.

5.2 BASIC PRINCIPLES

5.2.1 Notation

Let f2 be a data source that puts out symbols sk coded as integer numbers in the set {0, 1 .....

M - 1 }, and let S = {Sl, s2 .....

SN}

be a sequence of N random symbols put out by f2 [1, 4,

5, 21, 55, 56]. For now, we assume