This class implements the tag tree encoder. A tag tree codes a 2D matrix of integer elements in an efficient way. The encoding procedure 'encode()' codes information about a value of the matrix, given a threshold. The procedure encodes the sufficient information to identify whether or not the value is greater than or equal to the threshold.

The tag tree saves encoded information to a BitOutputBuffer.

A particular and useful property of tag trees is that it is possible to change a value of the matrix, provided both new and old values of the element are both greater than or equal to the largest threshold which has yet been supplied to the coding procedure 'encode()'. This property can be exploited through the 'setValue()' method.

This class allows saving the state of the tree at any point and restoring it at a later time, by calling save() and restore().

A tag tree can also be reused, or restarted, if one of the reset() methods is called.

The TagTreeDecoder class implements the tag tree decoder.

Tag trees that have one dimension, or both, as 0 are allowed for convenience. Of course no values can be set or coded in such cases.

'Declaration
 
Public Class TagTreeEncoder 

public class TagTreeEncoder