Shadow induction on optical see-through head-mounted displays

• Published in: Computers & graphics Vol. 91; pp. 141 - 152
• Main Authors: Ikeda, Sei, Kimura, Yuto, Manabe, Shinnosuke, Kimura, Asako, Shibata, Fumihisa
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2020
• Subjects: Augmented reality; Brightness induction; Optical see-through head-mounted displays; Virtual shadows; Optical see-through head-mounted displays; Virtual shadows; Augmented reality; Brightness induction
• ISSN: 0097-8493; 1873-7684
• DOI: 10.1016/j.cag.2020.07.003

•Dark shadows can be represented even on optical see-through head-mounted displays.•Users actually perceive virtual shadows darker than without augmentations.•Virtual shadows can improve the photo-reality of even transparent objects. [Display omitted] In this paper, we present two effects of illusion-based virtual shadows on a real surface for optical see-through head-mounted displays without devices that selectively reduce or intercept light rays from the real scene. The virtual shadows are based on the simultaneous brightness-contrast illusion in which a central region surrounded by a lighter one is perceived as darker than one without such a lighter region. To display a virtual shadow, a virtual object with a real image texture is placed around the shadow region as the lighter region to provide a sense of a darker area. We conducted two kinds of experiments to validate the feasibility of our method. The first experiment showed that users tend to perceive the virtual shadow part as darker than the surrounding area with the same physical luminance. The second experiment provided evidence that there are cases in which the virtual shadows can improve the reality of virtual objects.