Human eyes perceive colour through three types of cone cells: L (long-wavelength sensitive), M (medium-wavelength sensitive), and S (short-wavelength sensitive). Tristimulus values quantify colour by representing the levels of stimulation in these three types of cone cells when exposed to a particular colour. These values form the basis for various colour models and are essential in applications such as colour science, colour matching, and colour management.
- Tristimulus values are fundamental to colour measurement, whether in terms of the physiological response of the human eye to light or within systems used for precise colour matching and management in digital and physical media.
- Tristimulus values are often linked to the CIE XYZ colour space, which is a standard in colour science for translating cone cell responses into numerical values that represent colour.
- The notation for tristimulus colour values is typically represented using the three values X, Y, and Z in the CIE XYZ colour space. These values correspond to the quantified response of the L, M, and S cone cells, but they aren’t direct measurements of those responses. Instead, they are transformed to represent human vision in a way that can be standardized across various applications.
- Tristimulus values serve as the foundation for converting physical light and colour into numerical formats used in digital displays, photography, and printing.