Patent ID: 7558435

Claim:
A signal processing apparatus configured to adjust a signal level of successively arranged signals, said signal processing apparatus comprising a plurality of smoothing units for stepwise smoothing said successively arranged signals, wherein each of said smoothing units comprises: a specification unit configured to successively specify one of said successively arranged signals as a target signal; a determination unit configured to determine a plurality of adjacent signals out of said successively arranged signals at a predetermined interval based on said target signal specified by said specification unit; a flag setting unit configured to calculate differences in level between said target signal and said adjacent signals and between said target signal and signals arranged within said predetermined interval, from said adjacent signals toward said target signal, and determine whether the calculated differences are greater than a threshold value, wherein when at least one of the calculated differences is greater than said threshold value, said flag setting unit sets a flag to a corresponding adjacent signal, corresponding with said one of the calculated differences, as well as to another one of said adjacent signals arranged at a symmetrical position of said corresponding adjacent signal with respect to the target signal, and to adjacent signals arranged beyond said corresponding adjacent signal, when viewed from said target signal's position; a calculator configured to calculate a plurality of weighted averages of said target signal and said adjacent signals by utilizing a plurality of coefficients and generate a plurality of smoothed signals; a controller configured to control said calculator to generate said plurality of smoothed signals by using said target signal instead of said adjacent signals having said flags set; and a selector configured to select one among said plurality of smoothed signals as a result of setting by said flag setting unit.