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  Colour constancy is a function of the velocity of a moving surface

Werner, A. (2005). Colour constancy is a function of the velocity of a moving surface. In 18th Symposium of the International Colour Vision Society (ICVS 2005) (pp. 31-32).

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http://icvs05.free.fr/ (Abstract)
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Werner, A1, Author              
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 Abstract: Recently it has been demonstrated that colour constancy increases significantly if a surface moves across a textured background (Werner, 2004), as compared to an equivalent static condition (typical Mondrian presentation). This was found to be selective for object motion, suggesting the involvement of higher order motion mechanisms. Different motion processes can be distinguished on grounds of their temporal characteristics. In order to evaluate the involved motion processes, the temporal tuning of the effect of motion on colour constancy was determined. The background pattern consisted of a static heterochromatic checkerboard pattern (18 x 18 deg, Lmean = 19.3 cd/m 2) in front of which a testfield (1.8 1.8 deg, Ltest = 19.3 cd/m 2) moved horizontally with constant speed. The chromaticity of the testfield was identical to the mean chromaticity and was under standard condition achromatic (u* = 0.197, v* = 0.468). Colour constancy was tested for a simulated homogenous illumination change across the entire test-pattern from D65 towards a perceptually green illumination (u* = 0.166, v* = 0.472) resulting in a chromaticity shift of testfield and background along an equiluminant L/M axis (ΔE ∗ uv = 22.88). Colour constancy was measured using a hue cancellation method for the achromatic appearance of the testfield after a 5 s adaptation period to the new illumination, whereby the testfield moved continuously with one of 8 different speeds (0.3 to 14 deg sec-1). Three subjects with normal colour vision (Cambridge Colour Test) and normal visual acuity participated in the experiments. Colour constancy was found to increase nearly linearly with speed, reached a maximum value around 2 deg sec-1 and then dropped off sharply at higher speeds. The corner value for higher velocities (velocity at which the motion induced increase of colour constancy has dropped to 1 2 of its maximum value) is equivalent to a temporal frequency of 2 Hz. It is therefore consistent with the temporal properties of the relatively slow third order motion/feature tracking system, which can be linked to tracking the position of objects moving across a scene (Lu & Sperling, 2001; Seiffert & Cavanagh, 1999).

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 Dates: 2005-07
 Publication Status: Published online
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Title: 18th Symposium of the International Colour Vision Society (ICVS 2005)
Place of Event: Lyon, France
Start-/End Date: 2005-07-08 - 2005-07-12

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Title: 18th Symposium of the International Colour Vision Society (ICVS 2005)
Source Genre: Proceedings
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Pages: - Volume / Issue: - Sequence Number: 34 Start / End Page: 31 - 32 Identifier: -