Encoder, decoder and method

A method of encoding input data to generate corresponding encoded output data, characterized in that the method includes:

• (a) using an analysis unit for analysing one or more portions of the input data and directing the one or more portions to appropriate one or more encoding units, wherein the one or more encoding units are operable to encode the one or more portions thereat to generate the encoded output data;
• and
• (b) using at least one of the one or more encoding units to compute data values present in each portion received thereat, to subdivide the data values into at least two sets, to compute values of the data values in each set, and for each set to allocate the value for that set to all data values in that set, whilst retaining a spatial mask of the portion, and wherein the spatial mask and information representative of the values computed for the at least two data sets is included in the encoded output data.

A decoder for decoding encoded input data to generate corresponding decoded output data, characterized in that the decoder includes:

• an analysis unit for analysing one or more portions of the input data and directing the one or more portions to appropriate one or more decoding units, wherein the one or more decoding units are operable to decode the one or more portions thereat for generating the decoded output data, wherein,
• at least one of the one or more decoding units is operable to extract a spatial mask and information representative of values for at least two data sets included in the encoded input data, and for assigning values to elements in the mask pursuant to which of the sets the elements belong as defined by the mask.

A method of decoding encoded input data to generate corresponding decoded output data, characterized in that the method includes:

• (a) using an analysis unit for analysing one or more portions of the encoded input data and directing the one or more portions to appropriate one or more decoding units, wherein the one or more decoding units are operable to decode the one or more portions thereat for generating the decoded output data;
• and
• (b) using at least one of the one or more decoding units to extract a spatial mask and information representative of values computed for at least two data sets included in the encoded input data, and to assign values to elements in the mask pursuant to which of the sets the elements belong as defined by the mask.