An image processing method includes: acquiring a mosaic image photographed by image pickup means including an image pickup element in which a basic array pattern is repeatedly arranged in horizontal and vertical directions, storing first correction data containing a coordinate of a defective pixel and correction information associated with a position of the defective pixel in the basic array pattern, and second correction data containing a correction pattern corresponding to the correction information and indicating positions, relative to the defective pixel, of plural peripheral pixels that have a same color as the defective pixel, reading the correction pattern based on the correction information, calculating coordinates of the peripheral pixels based on the first correction data and the read correction pattern, extracting pixel values corresponding to the peripheral pixels at the calculated coordinates from the mosaic image, and calculating the pixel value of the defective pixel.