Abstract
Chromatic induction is observed whenever the perceived colour of a target surface shifts towards the hue of a neighbouring surface. Some vivid manifestations may be seen in a white background where thin coloured lines have been drawn (assimilation) or when lines of different colours are collinear (neon effect) or adjacent (watercolour) to each other. This study examines a particular colour induction that manifests in concomitance with an opposite effect of colour saturation (or anti-spread). The two phenomena can be observed when a repetitive pattern is drawn in which outline thin contours intercept wider contours or surfaces, colour spreading appear to fill the surface occupied by surfaces or thick lines whereas the background traversed by thin lines is seen as brighter or filled of a saturated white. These phenomena were first observed by Bozzi (1975) and Kanizsa (1979) in figural conditions that did not allow them to document their conjunction. Here we illustrate various manifestations of this twofold phenomenon and compare its effects with the known effects of brightness and colour induction. Some conjectures on the nature of these effects are discussed.
Highlights
The perceived colour and brightness of a surface are affected by the colour and brightness of an adjacent surface
The spreading diffuses from areas of any width
It is not blocked by a contour and is observed even with monochromatic figural units (Figure 3, left column)
Summary
The perceived colour and brightness of a surface are affected by the colour and brightness of an adjacent surface. The phenomenon is called “contrast” when the variations enhance the differences between the two neighbouring surfaces, whereas the term “assimilation” is used to indicate a stronger homogeneity. Simultaneous brightness contrast is the most common phenomenon belonging to the first category and is observed when similar targets are compared: one surrounded by a darker surface and the other by a brighter one. The first appears to be brighter than the second. Similar but stronger effects appear as “colour spreading” in some well-studied phenomena: “neon effect” (Van Tuijl, 1975; Varin, 1971), “watercolour effect,” (Pinna, Brelstaff, & Spillmann, 2001), and “flank transparency” (Wollschläger, Rodriguez, & Hoffmann, 2002)
Sign-in/Register to view highlights & summary 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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
