IMAGE SENSING APPARATUS WHICH PERFORMS DYNAMIC RANGE EXPANSION AND IMAGE SENSING METHOD FOR DYNAMIC RANGE EXPANSION

An image sensing apparatus which senses an object a plurality of times in different exposures to obtain a plurality of images and makes a single image with a widened dynamic range by processing the plurality of sensed images, generates a histogram of signal levels of an image sensed in a proper exposure by using a histogram generator, automatically decides whether a dynamic range expansion processing is to be processed or not on the basis of the generated histogram by using a dynamic range expansion deciding unit, determines a parameter for sensing another image of the object in an exposure which is different from the proper exposure in accordance with a decision by the dynamic range expansion deciding unit by using a parameter determination unit, and obtains a single image of the object by processing the image sensed in the proper exposure and the image sensed by using the parameter determined by said parameter determination unit an image processing unit. When an image sensing apparatus is not equipped with a photometer, a pre-sensing operation is performed, an image sensed in the pre-sensing operation is analyzed to find a proper exposure, and this image is also used in the dynamic range expansion processing. A part or whole image data of a plurality of images which are obtained as above and necessary for the dynamic range expansion processing are compressed by a compressing unit and the compressed image data is used in the dynamic range expansion processing.