Patent ID: 6990219

Claim:
An image capturing apparatus comprising: an image capturing section ( 1 ) for converting a shape of an object into an electrical quantity in accordance with a parameter value set in a parameter setting section ( 1 a ), and outputting image data representing an image corresponding to the shape of the object, said image capturing section comprises: a detection element ( 11 a ) for converting the shape of the object into an analog signal; and an A/D conversion circuit ( 14 ) for converting the analog signal output from said detection element into a digital signal in accordance with the parameter value set in said parameter setting section and outputting the signal as the image data, and the parameter value set in said parameter setting section includes a conversion range and conversion resolution in converting the analog signal into the digital signal; and a capture control section ( 3 a ) for receiving the image data output from said image capturing section, calculating an evaluation index for evaluating image quality of the image from the image data, and if the evaluation index falls outside a range of a preset reference value, changing the parameter value set in said parameter setting section so as to make the evaluation index fall within the range of the reference value to output image data which is received from said image capturing section and the evaluation index of which falls within the range of the reference value, wherein the evaluation index calculated by said capture control section is a histogram index generated from a histogram representing a density of the image, and said capture control section calculates, as the histogram index, a ratio between a maximum value on a side of the histogram where a density of the image is high and a minimum value immediately near the maximum value on a side where the density of the image is lower than the density representing the maximum value.