When One Eye Sees Less: Uncovering Perceptual Thresholds of Asymmetric Quality Degradation in 4K XR Displays

The rise of 4K XR displays has increased demand for highresolution content, raising network and computational costs. To address these challenges while preserving perceptual quality, this study proposes binocular asymmetric quality degradation, leveraging findings that perceived quality is dominated by the higherfidelity view and acuity differences between dominant and nondominant eyes. A total of 41 participants viewed four types of 4 K content (video clip, game, UI, web) under two conditions: both eyes receiving the original video, or one eye receiving a lower-resolution or higher-compression version. Participants selected which appeared higher in quality. Using the Just Objectionable Difference (JOD) scale, results indicated participants generally failed to notice quality degradation at one-third of the original resolution and across all tested compression levels. Content-specific differences emerged: for game content, resolution degradation was unnoticed at any level, whereas compression artifacts became noticeable from Constant Rate Factor (CRF) 60 onward. Additionally, comparing JOD values for dominant versus non-dominant eye-based asymmetric quality degradation revealed that preserving original resolution in the dominant eye improved perceived quality for UI content, whereas maintaining original compression quality in the dominant eye was more critical for game content. Finally, to evaluate the JOD results in an objective context, we examined the alignment between objective quality metrics and subjective asymmetry tolerances. Video Multi-Method Assessment Fusion (VMAF) showed the strongest correspondence; participants did not notice asymmetric quality degradation at a VMAF score of approximately 46.76, confirmed by an additional validation test. The study supports content-adaptive asymmetric quality degradation in XR to efficiently reduce computational overhead while maintaining visual fidelity.