| 摘要 |
<p>PROBLEM TO BE SOLVED: To minimize the alias effect of a color and to maintain resolving power by providing a second filtering area for adjusting the color frequency response of a digital image formation system to the other color. SOLUTION: An optical system 212 is provided with an aperture diaphragm 310 provided with an effective aperture size different for the respective colors. Thus, the aperture diaphragm 310 becomes a color dependent aperture diaphragm for introducing the a point image intensity distribution function of a size different for the respective colors. The color dependent aperture diaphragm 310 enables the passing of the different colors inside this digital image formation system through the aperture diaphragms of the different sizes and thus, the modulation transmission function response of the optical system 212 is changed for the respective colors. As a result, the possibility of generating an alias at a low frequency in the color of the low sampling frequency of the digital image formation system is lowered. The color dependent aperture diaphragm 310 can be called as a color alias prevention filter.</p> |
