A color graphic informing on the impact of electric lighting and coated glazing in complex architectural scenes

Abstract

The present work proposes a graphical indicator that provides descriptive information about the color content of architectural environments, and shows color shifts due to illuminant or glazing changes. This color graphic is in accord with representations recently developed in electric lighting to provide information on color rendering. Its originality lies in (1) including contextualization, (2) dividing the color space based on color naming, and (3) giving the user the opportunity to compare scenes with different correlated color temperatures. After describing the development steps of the color graphic, two case studies and three validation experiments are presented. While the application of the graphic highlights its interest in a building design process, the validation experiments identified potential improvements.

A Colour Graphic for Real Complex Scenes: Application to Led Illuminants

“…In our previous work (Cauwerts and Jost, 2018), consistency was observed between histogram distribution produced by the colour graphic and by people judgments. Small differences have been interpreted as due to achromatic content and presence of vegetation.…”

“…This section summarizes main calculation steps of the proposed colour graphic (Figure 1). For further details on the methodology, the reader can refer to the above-mentioned publication (Cauwerts and Jost, 2018).…”

“…Three experiments were conducted for validation purposes (Cauwerts and Jost, 2018). They highlighted a need for re-defining the boundaries between colour categories, and for distinguishing chromatic and achromatic content.…”

“…To improve colour rendition accuracy for real environments, we developed a new colour graphic for light source and glazing (Cauwerts and Jost, 2018). Instead of making predictions based on a predefined set of colour samples, the colour content of complex scenes is analysed.…”

Categorizing color shifts due to tinted glazing via dominant colors of the scene

“…The color graphic (Figure 4) developed by Coralie and Jost 18 follows a similar principle, but addresses the actual colors present in a complex scene rather than a fixed color palette. Instead of the a * b * color plane, it uses the PT plane of the IPT color space while categorizing colors into distinct bins of six basic colors (purple, blue, green, yellow, orange, and red) 18 . The color shift is identified by connecting the original reference colors with the modified color in the PT color space.…”