In a pixel unit, W, R, G, and B pixels are arranged in rows and columns. The pixel unit output W, R, G, and B signals obtained by photoelectrically converting light incident on the W, R, G, and B pixels. An edge detection unit determines a specific area having a W pixel provided with a white filter as a central pixel in the pixel unit, divides the specific area into blocks including the central pixel, and detects edge information as to whether there is an edge of an image in each of the blocks. A block select unit selects a block with no edge from the edge information. A ratio calculating unit calculates the ratio coefficients of the R, G, and B signals from the selected block. An RGB signal generator generates new R, G, and B signals from the W signal of the central pixel using the ratio coefficients.