Patent ID: 7230644
Filing Date: 2007-06-12
Classification: H04N

Abstract:
1. An image-sensing apparatus comprising: a photoelectric conversion device, having a plurality of photosensitive devices that produce electric signals in accordance with brightness of light incident thereon, for converting logarithmically the electric signals produced by the individual photosensitive devices; a brightness distribution evaluator for evaluating brightness distribution of the subject by determining frequencies of different brightness values sensed by the individual photosensitive devices in accordance with the electric signals output from the photoelectric conversion device, a determiner for determining a brightness range of the subject to be targeted by level conversion by detecting hem portion brightness of a subject in accordance with the brightness distribution evaluated by the brightness distribution evaluator, wherein the determiner calculates an effective area of the brightness distribution by determining the number of brightness frequency ridges in the brightness distribution of the subject and, if there is more than one brightness frequency ridge in the brightness distribution, removing each brightness frequency ridge having an integrated area smaller than a predetermined proportion of the integrated area of the largest brightness frequency ridge of the brightness distribution, and wherein the determiner determines the hem portion brightness based on the effective area; and a converter for performing level conversion on the electric signals for a single frame output from the photoelectric conversion device and for cutting at least a portion of the hem portion brightness of the electrical signals for the single frame output in such a way that the brightness range of the subject as determined by the determiner is adapted to a dynamic range of an output device used to reproduce an image.