An image processing technique for improving image resolution by increasing an effective number of pixels that represents a captured image. The technique involves obtaining a first exposure and at least a second exposure of an object. The image data of the second exposure differs from the image data of the first exposure in that a focal length for the second exposure differs from that for the first exposure. To the extent there exists a correlation, the image data of the second exposure is used for pixel data for each pixel of the image data of the first exposure requiring resolution improvement. When such correlation does not exist, pixel interpolation is performed using pixel data created by means of calculation for pixel interpolation positions.