Controlling the Color Appearance of Objects by Optimizing the Illumination Spectrum

Generally, in order to check variations such as changing the color of part of a product, there are only two methods:
(a) creating multiple product samples, or
(b) photographing the object and editing the image with photo retouch software and check the resultant image on a monitor.
The former incurred prototype production costs, while the latter faced the difficulty of accurately color reproduction on a monitor and replicating the material’s texture.

In our technology, it becomes possible to modify the vividness (saturation) and hue of specific colors by appropriately optimizing the illumination spectrum, The key feature is that users can observe color variations on the actual object, rather than on a displayed image on a monitor.

To make this possible, we discovered a “color enhancement factor” for the first time in the world. By precomputing the color enhancement factor and adjusting its weighting relative to a reference illumination spectrum simply adding or subtracting it, we can continuously vary the color appearance of only specific colors.

Fig. 1: Color enhancement factors

Fig. 2a: Coloring simulation

Fig. 2b: Coloring simulation

Fig. 3:Virtual Color restoration

Fig.4: Specific color change

This technology was implemented onstage of “ANREALAGE”, a Japanese fashion brand, for the official program of Paris Fashion Week 2024 Spring/Summer held in September 2023.