1. An image sensing apparatus designed to subject a given image to a dynamic range compression processing, comprising: an image sensor adapted to generate an electric signal depending on an incident light quantity, and have a photoelectric conversion characteristic which comprises a first region where an electric signal is output therefrom while being changed relative to the incident light at a first rate, and a second region where an electric signal is output therefrom while being changed relative to the incident light at a second rate which is less than the first rate; an illumination-component extractor for extracting an illumination component illuminating a surface of an object, from an original image consisting of an image picked up by the image sensor; a reflectance-component determiner for determining a reflectance component of the object surface based on the original image and the illumination component; a compressor for subjecting the illumination component to the dynamic compression processing; and an image producer for producing a new image corresponding to the original image, based on the illumination component subjected to the dynamic compression processing by the compressor, and the reflectance component extracted by the reflectance-component determiner, wherein the compressor is operable to subject to the dynamic compression processing at least an illumination component in the second region of the original image.