| 摘要 |
PROBLEM TO BE SOLVED: To evaluate a noise (roughness, granularity) included in an image with excellent correlation with a human sense by using a conventional color scanner or monochromatic scanner. SOLUTION: A colorimetric system conversion section 1 converts an RGB signal from a color scanner into an L*a*b* signal. A spectrum calculation section 2 calculates a spatial frequency component from the converted signal and a space frequency correction section 3 applies correction in response to the spatial frequency component of the visual sense system to the calculated spatial frequency component and an evaluation calculation section 4 integrates an output of the spatial frequency correction section 3 to calculate the evaluation for the a*, b* components. A brightness characteristic correction section 5 corrects the evaluation value of the brightness components and provides an output. |
