Question

Question 1: (12 Marks) Starting with an initialised coding Table 1 below, follow through the LZW algorithm step by step and complete table below in order to encode the following TWO different sequences: a) AAAAAAAAAAAAAA b) AABABBAABAABBB Note that the initial code for letter A is 65, and the corresponding initial code for letter B is 66. You should submit full and detailed solution in two different tables (one for each sequence). Table 1. LZW coding of the sequence Code | New coding table entry output Code Data Input data 5 11 12 13 14

Answer 1

If P+Q is not present in the dictionary then add a row for P+Q and assign a code for that and generate the code output for P character

And in next step assign P=Q

If P+Q is present in the new data table then no code output bit is generated for p. This case is represented by a tick in the code output column of above table, you may leave that cell blank also as per your choice

In the next step P=P+Q

We generate a code output whenever p+q is not in the new data table entry

I had explained how data is entered in the LZW table for your better understanding.