ENCODING AND DECODING OF SIGNIFICANT COEFFICIENTS IN DEPENDENCE UPON A PARAMETER OF THE SIGNIFICANT COEFFICIENTS.

摘要

A data encoding method for encoding an array of data values as data sets and escape codes for values not encoded by the data sets, an escape code comprising a unary coded portion and a non-unary coded portion comprises the steps of: setting a coding parameter defining a minimum number of bits of a non-unary coded portion, the coding parameter being between 0 and a predetermined upper limit; adding an offset value of 1 or more to the coding parameter so as to define a minimum least significant data portion size; generating one or more data sets indicative of positions, relative to the array of data values, of data values of predetermined magnitude ranges, so as to encode the value of at least one least significant bit of each data value; generating, from at least the part of each data value not encoded by the one or more data sets, respective complementary most-significant data portions and least-significant data portions, such that the most-significant data portion of a value represents zero or more most significant bits of that portion, and the respective least-significant data portion is dependent upon a number of least significant bits of that part, the number of least significant bits being greater than or equal to the minimum least significant data portion size; encoding the data sets to an output data stream; encoding the most significant data portions to the output data stream; and encoding the least-significant portions to the output data stream.