Colour Naming

Colour naming is the visual task that humans do when they assign linguistic labels (i.e. colour terms or colour names) to objects in order to describe their appearance. This problem has been studied from many disciplines, such as Anthropology, Linguistics, Physiology and Psychophysics. In Computer Vision, colour naming consists on the labelling of image pixels with colour names. The goal is to assign the same names that a human observer would assign.

A full parametric model has been defined on the CIE Lab space. On this model, each one of the 11 basic colour categories (i.e. White, Black, Red, Green, Yellow, Blue, Brown, Purple, Pink, Orange and Grey) is modelled with a fuzzy set characterized by a combination of sigmoids as membership function. Hence, for any given image pixel, the memberships to the 11 basic categories can be obtained and used by a decision function to assign a linguistic laber to the pixel.

The model has several applications such as segmentation, automatic image description, retrieval, tracking and human-machine interaction.

			BLUE GREEN PINK RED

 

Original image	Green	Pink	White
Labelled image	Red	Orange	Brown

 

Psychophysics for Colour Naming

In order to refine the proposed model, we are doing psychophysical experiments to accurately define the inter-colour regions of the colour-naming space. These experiments are done in our Psychophysics Lab in fully-controlled conditions. The goal is to precisely define the boundaries between basic colours for a mean English speaker.