PAINT UNEVENNESS EVALUATION VALUE CALCULATING METHOD, PAINT UNEVENNESS EVALUATION VALUE CALCULATING DEVICE AND PAINT UNEVENNESS EVALUATING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a paint unevenness evaluation value calculating method, a paint unevenness evaluation value calculating device and a paint unevenness evaluating method that can give evaluations consistent with conventional sensory evaluations and restrain inconsistencies in evaluation by using evaluation values quantitatively expressing the relative clearness of boundaries between brightness and darkness when light is reflected by a paint coat.SOLUTION: In a paint unevenness evaluation value calculating method, a paint coat is irradiated with light, a picture shot at an angle in which the regular reflection ray of the light does not come incident is partitioned into a plurality of regions, luminosity of each region is figured out and, on the basis of differences in luminosity between nearby regions, a value pertaining to the gradient of luminosity over the whole picture is figured out as the evaluation value of paint unevenness of the coat. When comparing a paint coat A where the luminosity variation is gradational and a paint coat B where the variation is abrupt, the paint coat B has a clearer boundary between brightness and darkness, accordingly the evaluation value of paint unevenness is worse. Quantitative evaluation of paint unevenness is thus made possible by the use of values pertaining to the gradient of luminosity figured out.