A method determining tone conversion characteristics of digital still camera from two pictorial images

Abstract

Tone conversion characteristics of a digital still camera are usually determined by taking a gray scale. We have developed a new method for determining a tone conversion characteristics of a digital still camera from two pictorial images of different exposures without a gray scale. Calculated characteristics obtained by the new method are compared to measured values for gray scale. The comparison demonstrates a good agreement between the characteristics and measured digital values except in a lower region where flare light may be added. The method can be applicable to color management of digital still cameras.