Hue-preserving image enhancement for the elderly based on wavelength-dependent gamma correction

The purpose of this study is to apply digital image processing to original images acquired with common digital devices to generate the resulting images that are easy for the elderly to see without using colorimetric values. Therefore, we propose an image enhancement method to improve color visibility of digital images for the elderly, taking account of their color vision characteristics. The proposed method consists of lightness conversion by adaptive gamma correction according to the effective luminance ratio of the young and the elderly, contrast enhancement using an S-shape function, and hue preservation processing in the RGB color space. The effectiveness of the proposed method is illustrated by comparing it with other conventional methods through experiments using many natural images.