A signal processing method that includes inputting sample values of a signal and considering the signal to have a plurality of portions. For each portion, a predetermined function is fitted to the sample values of that portion of the signal by calculating values of coefficients for that predetermined function. At least one statistical information function is evaluated for the signal to determine statistical information about the signal and the calculated coefficient values are used so that the form of the statistical information function has been determined for the predetermined function used to fit the signal portion and further includes using the statistical information obtained about the signal to process the signal.