Patent ID: 7636494

Claim:
A signal processing method which is executed by a signal processing device for calculation of an image signal intensity by processing image signals from pixels sequentially output from an image inputting device in which plural pixels for photoelectric conversion of incident light are arranged in the horizontal direction and the vertical direction, said signal processing device executing: a first step of calculating a maximum value, a minimum value and an average value of image signal intensities of plural pixels which are arranged around a certain pixel; and a second step of executing correction of said image signal intensity of said certain pixel by replacing said image signal intensity with a value calculated by multiplying said average value by a coefficient in a range of 1 to 0.8 when said image signal intensity of said certain pixel is larger than a value which is calculated by multiplying said maximum value by a first coefficient, and executing correction of said image signal intensity of said certain pixel by replacing said image signal intensity with a value calculated by multiplying said average value by a coefficient in a range of 0.8 to 0.5 when said image signal intensity of said certain pixel is smaller than a value which is calculated by multiplying said minimum value by a second coefficient, for making said correction in a manner that said correction of said image signal intensity of said certain pixel relative to said image signal intensities of said plural pixels arranged around said certain pixel cannot be recognized effectively.