Data Structure Visualization - Huffman Coding

Recommendation

Recommended

Link

http://www.cs.usfca.edu/galles/visualization/download.html

Delivery Method

Java Application

License

Unlicensed Sourcecode

Language

English

Author

David Galles

Institution

University of San Francisco

Project

Data Structure Visualization

RelationshipToProject

PartOfProject

Works

Yes

Description

Visualizes the encoding and decoding process in Huffman coding. Accepts user input for the message to encode. This message is parsed to construct a tree with the distinct characters in the message at the leaf level along with the frequency. The encoded message is then constructed from the graph. This is followed by a graphical illustration of the decoding process where the encoded message is converted back into the message using the codes assigned earlier during the encoding process. Supports both continuous animation mode and step wise mode. Lets the users to move the layout of the tree nodes though that doesn’t have any functional value.

Evaluation

Overall Good. The graphical process of encoding and decoding is intuitive and useful. The construction of the tree is however is not really clear. Huffman coding and especially, the tree construction during the encoding process is non-trivial. Hence, running explanations or pseudo-code tracing would have been very useful. It requires the user to view the tree construction phase very carefully and sometimes a number of times to get a clear understanding. Each node has a frequency count inside it. It would have been really useful to have the frequency count inside the code table displayed at the top right corner (at the end of the encoding process). Decoding process in general is very simple in Huffman coding. The visualization keeps it simple as well which is appreciated. A measure of the performance of Huffman in terms of the compression factor should have been given.

ActivityLevel

Animation; Step Control; User Data

GoodFor

Lecture Aid; Self Study; Debugging

Screenshots

Videos

References

HowToUse

First Visited

2006-09-01

Last Visited

2008-07-02

Last Updated

2006-04-05

Topic

HuffmanCodingTrees

Community

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