Assessing the temporal uniformity of CIELAB hue angle

Area of Science:

• * Color science and visual perception.
• * Human factors and psychophysics.
• * Image processing and display technology.

Background:

• * Previous research indicated CIELAB's inadequacy in describing perceived temporal color change speed.
• * CIELAB was not originally designed for evaluating dynamic color transitions in illumination.
• * Temporal uniformity of color spaces is crucial for accurate perception assessment.

Purpose of the Study:

• * To further investigate the temporal uniformity of the CIELAB color space.
• * To assess CIELAB's performance under specific viewing conditions relevant to its design.
• * To explore potential improvements for temporal uniformity in CIELAB and cone-excitation spaces.

Main Methods:

• * Human observers compared pairs of sequential temporal color transitions.
• * Stimuli were presented as a 4.3° square within a 4000 K adapting field.
• * Observers identified the transition perceived as faster.

Main Results:

• * CIELAB demonstrated a lack of temporal uniformity even under controlled conditions.
• * Color transitions with identical physical rates (ΔE*ab/s) were perceived at different speeds.
• * This confirms CIELAB's limitations in accurately quantifying perceived temporal color change.

Conclusions:

• * CIELAB is not temporally uniform for describing perceived color change speed.
• * Further research is needed to develop more perceptually uniform color spaces for dynamic stimuli.
• * Preliminary efforts are underway to improve uniformity in CIELAB and cone-excitation spaces (LMS, DKL).