Method and apparatus for digital data compression

A method of decompressing digital data, which digital data includes encoded quantized coefficients and associated quantization and quadtree information, the method including the steps of

• (a) decoding said quantization and quadtree information;
• (b) decoding said encoded quantized coefficents
• (c) inverse quantizing the decoded quantized coefficients in accordance with the quantization and quadtree information, wherein each quadtree leaf node has an associated quantization factor utilised in said inverse quantising of said decoded quantized coefficients;
• and
• (d) inverse transforming the inverse quantized coefficients.

An apparatus for decompressing digital data, which digital data includes encoded quantized coefficients and associated quantization and quadtree information, the apparatus including;

• means for decoding said quantization and quadtree information;
• means for decoding said encoded quantized coefficents
• means for inverse quantizing the decoded quantized coefficients in accordance with the quantization and quadtree information, wherein each quadtree leaf node has an, associated quantization factor utilised in said inverse quantising of said decoded quantized coefficients;
• and
• means for inverse transforming the inverse quantized coefficients.

A computer program product including a computer readable medium having recorded thereon a computer program for decompressing digital data, which digital data includes encoded quantized coefficients and associated quantization and quadtree information, the computer program product including:

• means for decoding said quantization and quadtree information;
• means for decoding said encoded quantized coefficents
• means for inverse quantizing the decoded quantized coefficients in accordance with the quantization and quadtree information, wherein each quadtree leaf node has an associated quantization factor utilised in said inverse quantising of said decoded quantized coefficients;
• and
• means for inverse transforming the inverse quantized coefficients.