Chromaticity or Chroma:

This property of color tells us how pure a hue is. The absence of white, black, or gray present in a color is said to have high chroma and will appear very vivid.

CMYK:

Colors that are mixed with paints, pigments or inks, CMY or cyan/magenta/yellow, is the color system/model. Black, symbolized by “K”, is substituted for equal parts of CMY.

Color:

Characteristic of light determined by the light’s spectral composition and the interaction with the human eye. Hence, color is a psychophysical phenomenon, and perception of color is subjective.

Color Temperature:

The concept of color temperature arises from the apparent color changes of an object when it is heated to various temperatures. When the temperature of an object increases, the emitted radiation changes which result in the change of color. A special class of incandescent (glow when hot) object emits radiation with 100 percent efficiency when heated; scientists call this ideal full radiator as blackbody radiator.

Complementary Colors:

Two colors that when mixed together produce a neutral gray or white.

HSL:

HSL or hue/satuation/lightness is color system/model usually consistent with how the human eye sees color.

Hue:

The property of color that we are actually asking about is “hue”. For example, when speaking about colors that are red, yellow, green, and blue, we are talking about hue. Different hues are caused by different wavelengths of light.

Hunter Lab Color Space:

The Hunter Lab color space was developed in 1948 by R.S. Hunter as a uniform color space which could be read directly from a photoelectric colorimeter (tristimulus method).

L*a*b* Color Space:

The L*a*b* color space (also referred to as the CIELAB space) is one of the uniform color spaces defined by the CIE in 1976.

L*C*h Color Space:

The L*C*h color space uses the same diagram as the L*a*b* color space, but uses cylindrical coordinates. Lightness L* is the same as L* in the L*a*b* color space.

L*u*v* Color Space:

The L*u*v* color space (also referred to as the CIELUV space) is one of the uniform color spaces defined by the CIE in 1976.

Luminance:

Sometimes used when referring to the brightness/lightness of a color.

Primary Colors:

The colors that are seen when sunlight is separated by a prism are called spectral colors. These spectral colors are red, orange, yellow, green, blue, indigo, and violet. These ROYGBIV colors are often reduced to three “red, green, and blue-violet” which are the primary colors for the additive color system in light. The primary colors for the subtractive color system (paint/pigment/ink) are “cyan, magenta and yellow.

RGB:

RGB or red/green/blue is typically used when referring to projected light and is categorized as a color system/model.

Saturation:

This property of color tells us how a color looks under certain lighting conditions and is related to chromaticity. This property of color can also be called intensity. Saturation should not be thought of in terms of of light and dark, but rather in terms of pale or weak.

Tints, Tones and Shades:

These terms describe how the a color varies from its original hue. If white is added to a color, this lighter version is called a tint. If the color is made darker by adding black, then it’s referred to as a shade. When gray is added, each gradation gives you a different tone.

Tristimulus Colorimetry:

Tristimulus colorimetry is based on the three component theory of color vision, which states that the eye possesses receptors for three primary colors (red, green, blue) and that all colors are seen as mixtures of these three primary colors.

The most important system is the 1931 Commission Internationale I’Eclairage (CIE) system, which defined the Standard Observer to have color-matching functions x(*), y(*), and z(*) as shown in Fig. 2.4.4.1. The XYZ tristimulus values are calculated using these three standard observer color matching functions. XYZ tristimulus values and the associated Yxy color space form the foundation of the present CIE color space.

Uniform Color Space:

A color space in which equal distances on the coordinate diagram correspond to equal perceived color differences.

Value:

This property of color tells us how light or dark a color is based on how close it is to white.

 

Illuminance:

This is a measure of the concentration of luminous flux falling upon a surface.

Irradiance:

This is a measure of radiant flux incident on an object’s surface (radiant flux per unit area).

Luminance:

Also known as photometric brightness, luminance is a measure of the flux emitted from, or reflected by, a relatively flat and uniform surface. Luminance may be thought of as luminous intensity per unit area.

Luminous Flux:

A source of light radiates energy in the form of electromagnetic waves.

Luminous Intensity:

This expresses the power of a light source. It is defined as the quantity of luminous flux emitted in a given direction per solid angle (in steradian).

Photometry:

The measurement of the psychophysical attributes of electromagnetic energy that is visible to the human eye.

Radiance:

This is a measure of the total radiant intensity per unit projected area.

Radiant Flux:

This is the total radiant power emitted from a source or received by a surface. It can also be defined as the rate of flow of radiant energy through a certain area or out of a certain solid angle.

Radiant Intensity:

It is defined as the directed angular density of radiation from a source. The radiant intensity in a given direction is the sum of the power contained in all the rays (cones) emitted in that direction by the entire source (i.e., power per solid angle).

Radiometry:

The science of the measurement of electromagnetic (EM) radiation.

Spectral Irradiance:

This is a measure of the total radiant intensity per unit projected area.

Spectral Radiance:

The radiance of a light source is a single value which is the sum of all energy measured over a spectrum. The individual energy values at a particular wavelength in nanometer (nm) can be determined by a spectral radiance measurement.

Spectroradiometry:

The measurement of light energy at individual wavelengths within the electromagnetic spectrum. It can be measured over the entire spectrum or within a specific band of wavelengths.

 

No glossary terms yet. Coming soon.