Improving visual content accessibility for low-vision users in the MPEG-21 multimedia framework
Seungji Yang, Jong-Soo Choi, Yong Man Ro, Soo-Jun Park · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2008
An image content adaptation for visually impaired people based on the MPEG-21 Digital Item Adaptation (DIA) standard is proposed. The content adaptation mainly considers spatial contrast vision characteristic of users, which is represented by a contrast sensitivity function (CSF). There are three key contributions of the paper. First, the visual perception of users who have different spatial contrast vision abilities is simulated by incorporating the HVS model proposed by Pattanaik et al. Second, to measure spatial contrast vision, and thus realizing personalized content adaptation depending on the severity of the visual ability of individual user, CSF is measured on computer-based environment. The measured spatial contrast vision symptom and its severity, is represented in an interoperable way by using an example of extended description tool provided by the MPEG-21 DIA specification. Third, the content adaption is also proposed, which is personalized in a sense that the adapted content would be optimized to the given description of a particular symptom and its severity. To assess the effectiveness of the proposed methods, we performed a number of experiments targeting users with a low vision and showed how to determine and describe the CSF parameters. Furthermore, statistical experiment is performed to verify the effectiveness of the proposed adaptation process for users with the low vision symptom.