A pixel section outputs R, G and B signals which are obtained by photoelectrically converting light incident on R, G and B pixels. An adding section determines a prescribed area in which a certain pixel is set as a central pixel, and adds the R, G and B signals from the central pixel and peripheral pixels arranged on the periphery of the central pixel in the prescribed area in order to produce an addition signal. A ratio calculating section calculates an average value of each of the R, G and B signals, and a ratio coefficient of the average value of each of the R, G and B signals to a total value of the average values. An RGB generating section generates a new R signal, G signal and B signal by using the addition signal and the ratio coefficients calculated by the ratio calculating section.