المحاضرة الرابعة: نظرية المعلومات

THE SOURCE CODING PROBLEM
Example
Let U be a source taking values in {A, B, C, D} with probabilities ½, ¼, 1/8 and 1/8.
1,000 outputs of U are to be stored in the form of a file of binary digits, and one seeks
to reduce the file to its smallest possible size.
First solution
There are 4 ?????? symbols to be encoded. Thus, each of them can be associated with
a word of two binary digits as follows:
THE SOURCE CODING PROBLEM
Example
Let U be a source taking values in {A, B, C, D} with probabilities ½, ¼, 1/8 and 1/8.
1,000 outputs of U are to be stored in the form of a file of binary digits, and one seeks
to reduce the file to its smallest possible size.
First solution
There are 4 ?????? symbols to be encoded. Thus, each of them can be associated with
a word of two binary digits as follows:
THE SOURCE CODING PROBLEM
Example
Let U be a source taking values in {A, B, C, D} with probabilities ½, ¼, 1/8 and 1/8.
1,000 outputs of U are to be stored in the form of a file of binary digits, and one seeks
to reduce the file to its smallest possible size.
First solution
There are 4 ?????? symbols to be encoded. Thus, each of them can be associated with
a word of two binary digits as follows: