The overall appearance of any object is a combination of its chromatic attributes (color) and its geometric attributes (like gloss, shape, texture, shininess, haze, and translucency). Thus, both types of attributes should be measured and accounted for when making visual or instrumental assessments of
Chromatic attributes are those attributes associated with color. They are normally divided into three components:
• Lightness, whether the color is closer to black or white. Sometimes the term 'value' is used rather than lightness.
• Hue, the perceived color of an object, such as red, green, blue, yellow, or orange.
• Saturation, the degree of departure from gray. This is the vividness or purity of a color. For example, bright candy apple red is more saturated than dull brick red.
In general, it is the chromatic attributes of appearance that are measured using HunterLab spectrophotometers and colorimeters, although the chromatic attributes of an object can never be completely separated from its geometric attributes.
Geometric attributes are those attributes associated with distribution of light from an object. For instance, a flat cotton weave fabric is very different geometrically from a corduroy. A glossy photo print looks quite different than a matte one. There are many geometric attributes. Several examples are provided below.
• Gloss, the property of a surface responsible for shiny or lustrous appearance.
• Haze, the scattering of light within the surface of a nearly clear sample that is responsible for a cloudy appearance.
• Directionality, the characteristic of a sample which causes it to look differently depending on which direction it is turned
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