Index of Metallic Taste from Lightness Distribution of Real Images

Abstract

the designers, etc. The color management of foils has also depended on the visual judgement due to the lack of an index and the dependence has decreased productivity of this market. These inefficiencies have caused time loss and cost and interfered with market expansion. This fact strongly prompted us to study which physical features of metallic prints induce the metallic taste and then construct the index. We now suggest a metallic taste index (MTI) possessing a linear correlation with the perceived magnitude. To construct the index, we focused on the lightness distribution of the reflection as a feature of the unique metallic appearance. Figure 1 a)-b) shows a comparison of the lightness distribution property between the common colors and metallic colors. Regarding the common colors, almost all the incident light is reflected as diffuse light and the distribution becomes nearly isotropic. On the other hand, the lightness distribution of metallic colors is quite anisotropic, and the incident light is predominantly reflected around specular. This is significantly characteristic for metallic images, and a recent study demonstrated that specular, roughness and Abstract: As one of the high-value-added prints, embellished metallic prints via digital on-demand metallic foil printing have been of interest. Due to their eye-catching appearance, they are suitable for commercial prints, such as cosmetic packages and advertisements. Despite an expanding market, color management of the metallic prints still depends on visual judgment and the prescribed index of metallic taste has not yet been defined. Since the absence of an index has decreased productivity of people involved in this market, such an index based on perception has been needed. Thus, we suggest an index calculated from the lightness distribution of the real metallic images. The index possessed a linear correlation with perception and distinguished several appearances of the metallic images. It should be useful for several creative scenes in this market.