Chapter 5 - Colour Detection and Recognition Flashcards
Why do strawberries look red?
They absorb all other wavelengths except for red
What is monochromatic light?
Light that consists of only one wavelength
What is heterochromatic light?
Light that consists of more than one wavelength
What is white light?
light that contains wavelengths across the entire visible spectrum (heterochromatic light) but with no dominant wavelength, therefore it is seen as white
What is achromatic light?
White light, along with all other shades of grey, are achromatic
What is the reflection spectrum?
Proportion of light that a surface reflects at each wavelength
- the dominant wavelength reflected from an object determines its perceived colour
How do we see colours on a monitor?
With red, green or blue pixels
What are the perceptual experiences of colour represented as?
Hue, saturation and brightness
What is hue?
the quality defined as colour, most closely associated with the wavelengths of light
What is saturation?
the vividness (purity) of the hue
What is brightness?
the amount of light
What is the CIE colour space?
developed in 1937 to standardize colour space by representing any colour as an (x,y) coordinate
- brightness is not represented in the CIE colour space because we would need a third dimension to describe it
What is a subtractive colour mixture?
certain wavelengths of light reflected from the surface have been subtracted (absorbed) by surfaces in the mixture
What is additive colour mixture?
The perceived colour of the mixture results from adding together all the wavelengths of light in the mixture (like a computer screen)
What are complimentary colours?
pair of colours, that, when combined together, are perceived as a shade of grey (ex. blue+yellow)
