Analyzing afterimage strength and duration test results with k-means clustering

Garai Lőrinc and Horváth András (2023) Analyzing afterimage strength and duration test results with k-means clustering. In: Szemelvények a BGE kutatásaiból II. kötet. Budapesti Gazdasági Egyetem, Budapest, pp. 103-112. ISBN 978-615-6342-76-8

Preview

Text
Garai-Horváth.pdf - Published Version
Download (553kB) | Preview

Abstract

Afterimages are common and frequent perceptual phenomena of everyday life. A typical appearance is the negative “ghost” image of a bright light source when we turn away from it. In the case of significant colour contrast, the afterimage can be coloured. The strength of the perceived false image decreases gradually and completely disappears in a 10–100-s timescale. The underlying processes have multiple components: a quick adaptation on the retinal level, and a slower adaptation on the cortical level. The phenomenon of afterimage has a potential application in ergonomic and visual design fields. In our former research, we examined the effect of gender and age on afterimage strength and duration. We asked test subjects to observe and evaluate the duration and “strength score” of the same light-transitions. Two sets of experiments were performed: colour-colour transitions with 41 and colour-grey transitions with 16 test subjects between 19 and 62. We found that gender has no measurable influence, but age makes a difference to a great extent. Both experiments confirmed that over 40 years the average duration of colour afterimages decreases. In our current study we examined the dependence of afterimage parameters on colourimetry parameters. We found that duration and strength depend on chroma change, but the direction of the colour transition in the a*-b* (green-red and blue-yellow) plane is also essential. The importance of magenta-green colour transition was revealed by k-means cluster analysis, but the number of tests should be increased for a final conclusion.