On just noticeable difference for bionic eye

Abstract

We propose to use Just Noticeable Difference (JND) as the principle in visualizing results for image processing modules for prosthetic vision. Current Bionic Eye hardware implants have limited levels of separately perceivable brightness (i.e., low dynamic range in visualizing images). Therefore, it is important to ensure that the critical contrast must remain perceivable by maintaining of visual differences in downsampled images with reduced dynamic range. JND provides a mathematical framework for these psychophysics events. An increase by 1 in JND space corresponds to the smallest detectable change in visual space (i.e., just noticeable). Combining this principle and the dynamic range constraint, we cast the visualization problem to a linear optimization problem, which enables us to generate optimal visualization images. We demonstrate the usefulness of this principle on visualizing ground-plane segmentation. Experiments show that the proposed principle effectively provides critical visual information at different dynamic ranges, and generates consistent results for image sequences.