1. An image-processing apparatus comprising: taken-image acquisition means for acquiring a taken image; to-be-processed area setting means for carrying out an analysis on the taken image and for using a pixel area of a photographed-subject image of a specific type in said taken image as a to-be-processed area of an image conversion process in accordance with a size of said photographed-subject image if a result of said analysis indicates that said photographed-subject image exists in said taken image; and conversion means for carrying out said image conversion process on said photographed-subject image with said pixel area thereof used as said to-be-processed area in order to generate a post-conversion image obtained as a result of said image conversion process.