Improving the color quality evaluation of holographic prints with light pillars

Area of Science:

• Color Science
• Visual Perception
• Print Technology

Background:

• Understanding human visual perception of color differences is crucial for quality control in print production.
• Holographic prints present unique challenges for color difference evaluation due to their complex visual effects.

Purpose of the Study:

• To investigate the influence of lightness, chroma, and hue differences on human perception of color in holographic prints.
• To optimize standard color difference formulas (CIELAB and CIEDE2000) for holographic print evaluation.
• To recommend specific tolerance values for color difference evaluation of holographic prints.

Main Methods:

• Prepared 84 pairs of holographic prints within 3.0 CIELAB color difference units from nine cigarette packaging products.
• Conducted a color difference evaluation experiment with 22 experienced observers.
• Applied parametric factor and power function optimization using the STRESS index on combined datasets (264 pairs).

Main Results:

• Observers demonstrated higher sensitivity to hue differences compared to lightness and chroma differences.
• Optimized CIELAB formula factors: kL:kC:kH = 1:1:0.32.
• Optimized CIEDE2000 formula factors: kL:kC:kH = 1:1:0.34.

Conclusions:

• Recommended hue difference tolerances: ΔH*ab of 0.8 (colorized) and 0.3 (achromatic).
• Recommended CIEDE2000 tolerances: ΔH00 of 0.54 (colorized) and 0.4 (achromatic).
• These optimized formulas and tolerances are particularly effective for evaluating holographic prints within 3.0 CIELAB units.