Image quality enhancement technique for optical see-through displays across different ambient luminance levels

This study investigates ambient-light–induced image-quality degradation in optical see-through (OST) displays and presents a perceptually driven enhancement method. Luma and chroma of input images are adjusted via power-law transformations to compensate for contrast loss and chroma reduction caused by additive mixing with ambient light. The adjustment parameters were empirically derived through psychophysical experiments and modeled using ambient light level (SR, %) and average image luma. Experimental results show that the proposed adjustment significantly improves perceived image quality across various OST viewing conditions. Analysis of observer feedback reveals that preferences are not driven by a simple maximization of brightness. Instead, the selections are guided by specific qualitative criteria, such as maintaining readability in dark regions, preserving highlight textures, and balancing light–dark organization for depth cues. These findings suggest that effective OST image compensation requires an approach that prioritizes these perceptual factors over global intensity adjustments.