Methods of and apparatus for encoding and decoding data in data processing systems

摘要

To encode and compress a data array 30, the data array 30 is first divided into a plurality of blocks 31. A quadtree representation is then generated for each block 31 by initializing each leaf node of the quadtree to the value of the data element of the block 31 of the data array 30 that the leaf node corresponds to, and initializing each non-leaf node to the minimum value of its child nodes, and then subtracting from each node except the root node the value of its parent node. A set of data indicating the differences between respective parent and child node values in the quadtree representing the block of the data array is then generated and stored, together with a set of data representing a quadtree indicating the number of bits that have been used to signal the respective difference values.

主权项

1. A method of encoding an array of data elements for storage in a data processing system, the method comprising:
generating at least one tree representation for representing the array of data elements, the tree being configured such that each leaf node of the tree represents a respective data element of the data array, and the data values for the nodes of the tree being set such that the data value that the tree indicates for the data element of the data array that a leaf node of the tree represents is given by the sum of the data values in the tree for the leaf node and each preceding parent node in the branch of the tree that the leaf node belongs to; generating and storing data representing the at least one tree representing the data array as an encoded version of the array of data elements; and for at least one parent node of the tree, interleaving bits representing the data values of child nodes of the parent node of the tree with each other in the stored data representing the at least one tree representing the data array.