Question

Please and thanks you.Can anyone explain me this question in detail if we use only one tree for different messages.a Huffman tree was designed using frequencies taken from a given message, and for every new message we would have to build a new tree. Imagine instead that we had built one tree to encode all different messages (in English, say). How would you determine what that Huffman tree should look like? What would be the advantages and disadvantages of building one tree to encode all messages?

Answer 1

Hello there,

Huffman coding is a lossless compression algorithm and its sole purpose is to avoid all possible ambiguities while decoding the generated bit stream.The input given to a Huffman code is an array of unique characters along with their frequency of occurrences and the output obtained is a Huffman tree.This algorithm deals with the input, character by character.

The frequencies are assigned in such a way that the character that occurs the most number of times get assigned to the smallest code and the character that has the least frequency gets assigned to the largest code.

As you have already mentioned, Huffman tree is generated by assigning variable length codes to input characters whose lengths are based on the frequency of occurrences of the corresponding characters.Since in each message the frequency of occurrence of a character might be different, it is required to create a separate Huffman tree for every message in order to preserve the unambiguous nature of this methodology and to avoid all possible difficulties while the decoding process.

The disadvantage of building a single tree for multiple messages would be the impracticality in generalizing the frequency of occurrence of different characters in different messages.If it was possible to build a single tree for encoding different messages, It would increase the whole efficiency and robustness of the algorithm.