Image lightness conversion and sharpening taking account of visual features of elderly person
Proc. of 2019 IEEE International Conference on Image Processing (ICIP2019), pp.4709-4713
D. Moriyama, C. Ueda, T. Azetsu, N. Suetake, E. Uchino
The performance of human visual functions degrades with age. For example, the visual field becomes dark owing to a decrease of the amount of light received. Moreover, objects appear to be hazy by a decrease in the contrast sensitivity. In particular, the contrast sensitivity decreases remarkably as the spatial frequency increases. In this paper, we propose an image enhancement method which consists of a lightness conversion and an amplification of high spatial frequency components to take account of visual characteristics of elderly persons. Concretely, the lightness conversion is conducted within the color gamut by using a tone mapping. In addition, a sharpening based on the inverse characteristic function of the sensitivity decay curve is applied. The effectiveness of the proposed method is verified by experiments using several digital images.