The Control Components of AHuffman
Input String
Displays the input string. The current character being processed is highlighted in blue.
Output String
Displays the compressed string.
Instructions
Displays a description of the major steps that are taken when a single character is processed. Processing of an inpt symbol is done in two phases: 1) Encoding: The information for the encoding can be obtained by consulting "Tree in Previous State"; 2) Updating the Huffman Tree: After the encoding of the current character, the Huffman tree is updated. The updated tree will appear in "Tree". "Instructions" will display a line if a switching of subtrees has occurred. It will display an asterisk followed by "Swapping of nodes X and Y" for each switching of subtrees X and Y that takes place during the execution of the update procedure.
Tree
Displays the current adaptive Huffman tree generated by the algorithm. Note that the tree displayed here is AFTER the current character has been processed. In other words, after the encoding of the current character and after the update procedure has updated the Huffman tree.
Display Tool
The small pop-up window entitled "Tree" is used for better viewing the tree. This window always displays the whole tree but in a much smaller scale. The part of the tree inside the red rectangle, is the same as its enlargement in the main window. When the user moves the rectangle in the small window, the view port of the original tree in the main window will be adjusted immediately. In other words, the user can adjust the view port of the main window by using the fourth window instead of having to adjust the scrollbars.
Tree in Previous State
Displays the tree constructed in the previous step of the algorithm. It only shows up when the user runs the algorithm in the "Step" mode.
Send comments and suggestions about AHuffman to khuri@mathcs.sjsu.edu or hsu0832@sundance.sjsu.edu