1. A method for processing an image to detect a skin area of a person in the image, the method comprising: detecting a face area of the person in the image; calculating a skin color reference value based on at least one pixel in the detected face area; setting at least one pixel in a vicinity of an area extension blocking area of the detected face area of the person as a start point so that area extension processing is applied in the vicinity of the area extension blocking area; and detecting a skin area of the person in the image by searching for successive pixels having skin color from the set start point and extending the skin area, wherein, in a case where a color of the set start point is not within a predetermined range from the skin color reference value, the set start point is not used as the start point of the area extension processing.