Patent ID: 8601042

Claim:
A signal processing device for performing filter processing operations on an input signal to generate an output signal, comprising: a plurality of filter processing means for performing a plurality of filter processing operation on said input signal and generating a plurality of filtered signals; one or more subtracting units for generating a difference signal for each of the plurality of filtered signals, wherein each difference signal is the difference between each of the plurality of filtered signals and the input signal respectively; and generating means for generating said output signal by adding a correction value to the input signal, wherein generating said correction value comprises: determining a maximum value of the difference signals for the plurality of filtered signals and a minimum value of the difference signals for the plurality of filtered signals; determining whether a product of the maximum value and the minimum value is greater than zero, zero, or less than zero; and setting the correction value to one of either the maximum value or the minimum value having the largest absolute value if the product is greater than zero or zero, and setting the correction value to the sum of the maximum value and the minimum value if the product is less than zero.