Evaluation of Light Fastness Using Digital Image Analysis

Light fastness has been traditionally estimated by visual assessment using blue scale method. Considering that visual experiment is a time consuming process and the inconsistency between observer’s viewpoints, it is of interest to have a computational method. In this paper, digital image analysis is applied to estimate light fastness of textile samples. To perform it, scanned image of a Standard Blue Scale was captured before and after exposure in the SunTest. The color values of each blue scale grade and its faded part images were evaluated and their differences applied as the value of that grade. In this way, a numeric blue scale is obtained which is composed of color difference values. To estimate the light fastness of a sample, the color difference between its images before and after exposing to day light is computed. Then the corresponded light fastness grade can be obtained by comparing the sample color difference with the numeric blue scale. The proposed method deduces stable values and experimental results show acceptable precision in comparison to traditional method. In addition, by using a numeric blue scale it wont be necessary to use that expensive standard blue scale in each experiment and experimental cost can be reduced.

کلیدواژه ها:

Light fastness ، Image analysis ، Blue scale ، Textile