Abstract
Color enhancement factors are spectral components that modulate the spectral power distribution (SPD) of illumination for interactive color saturation control. They can enhance more than one target color simultaneously or independently while maintaining the current color appearance. However, the color enhancement factors obtained in our previous work depended on the lighting system. Moreover, the effects of color muting, such as decreasing saturation of the target color, were limited because the color enhancement factors were optimized to increase color saturation. We overcame these two issues and succeeded in implementing color enhancement factors that can both enhance and mute color saturation. First, we conducted detailed simulations of color saturation enhancement and muting to determine parameters for calculating the color enhancement factors (e.g., the center wavelength and full-width at half-maximum) and assessed their potentiality. The results showed that maximum variations of color muting became almost the same as those of color enhancement. We also found that SPDs of illumination for increasing and decreasing color saturation of red, green, and blue had three peaks, respectively, and that they appeared for enhancement and muting alternately. In addition, the color enhancement factors for enhancing and muting color saturation were roughly symmetric. We then performed experiments using a newly designed 12-color LED lighting system, and the results showed color enhancing and muting effects. Finally, we demonstrated color restoration of discolored cultural heritage and coloring simulation of industrial products.
Highlights
Color enhancement techniques for captured images are useful for enhancing an observer’s impression or attracting an observer’s attention, and many methods have been developed in recent years.[1,2,3,4] These methods require image capturing, geometrical correction, and color reproduction and display using imaging devices
(2) We introduce color enhancement factors optimized for decreasing color saturation and achieve that the maximum variations of color muting become almost the same as those of color enhancement
We describe the details of this idea mathematically and present a successful implementation of color enhancement factors for both color enhancement and muting using a combination of LEDs whose center wavelengths are different
Summary
Color enhancement techniques for captured images are useful for enhancing an observer’s impression or attracting an observer’s attention, and many methods have been developed in recent years.[1,2,3,4] These methods require image capturing, geometrical correction, and color reproduction and display using imaging devices. In adding visual effects properly, there are mainly two issues: an image corresponding to the visual effect has to be generated, and position gaps between the generated image and the real object have to be corrected. A color enhancement factor is a spectral component corresponding to a variation in the color saturation of a target color and is calculated using metameric conditions among several colors. Once the effect of color enhancement against a target color is known, the color difference between before and after enhancing a color of an object is evaluated on the CIE aÃbà color space
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
