In previous human skin models, it has been suggested that the colour of human skin is mostly determined by the concentration of melanin in the epidermal layer combined with the concentration of hemoglobin in the dermal layer. The colour of facial skin changes significantly with changes in the light incident upon it. In this paper we propose a method of normalizing the skin tones of human faces ...

Combinations of microstructural and pigmentary components of barbs create the colour displays of feathers. It follows that evolutionary changes in colour displays must reflect changes in the underlying production mechanisms, but rarely have the mechanisms of feather colour evolution been studied. Among bluebirds in the genus Sialia, male rump colour varies among species from dark blue to light ...

OBJECTIVES The objective of this study was to evaluate the discolouration effects of artificial saliva, granule lemon juice, coffee (without sugar), coca cola, sour cherry juice, fresh carrot juice and red wine on resin-based composite materials that are commonly used in restorative dentistry. METHODS Colour of four brands of resin composites (Filtek Z 250 (3M Espe), Filtek Supreme (3M Espe),...

BACKGROUND Plumage coloration is important for bird communication, most notably in sexual signalling. Colour is often considered a good quality indicator, and the expression of exaggerated colours may depend on individual condition during moult. After moult, plumage coloration has been deemed fixed due to the fact that feathers are dead structures. Still, many plumage colours change after moult...

Colour is an important cue in many applications in machine vision and image processing. Nevertheless, colour greatly depends upon illumination changes. Colour constancy goal is to keep colour images stable. This paper’s contribution to colour constancy lies in estimating both the set and the likelihood of feasible colour mappings. Then, the most likely mapping is selected and the image is rende...

The history of colour science has its origins in the era of Greek philosophers Plato and Aristotle. Newton, Helmholtz, Hering, Munsell, Land and Ostwald continued with the scientific approach as it was them who provided the basis for understanding and comprehension of the colour phenomena [1, 2, 3]. They proved that the perception of a colour will depend and change depending on the parameter ch...

The highest possible resolution for printed colour images is determined by the diffraction limit of visible light. To achieve this limit, individual colour elements (or pixels) with a pitch of 250 nm are required, translating into printed images at a resolution of ∼100,000 dots per inch (d.p.i.). However, methods for dispensing multiple colourants or fabricating structural colour through plasmo...

Two kinds of constancy underlie the everyday perception of surface colour: constancy under changes in illuminant and constancy under changes in surface position. Classically, these two constancies seem to place conflicting demands on the visual system: to both take into account the region surrounding a surface and also discount it. It is shown here, however, that the ability of observers to mak...