saturationchroma

Saturationchroma is a term found in color science and digital imaging to describe a single scalar metric intended to reflect the vividness or intensity of a color by integrating aspects of saturation and chroma. It is not a universally standardized term, and there is no single agreed-upon definition. Traditional color descriptors distinguish saturation, used in HSV or HSL, from chroma, used in perceptual spaces such as CIELAB or CIELCh.

Definition and calculation

A common generic approach defines saturationchroma as a Euclidean combination of normalized saturation and chroma. For example, SC = sqrt( (S')^2 + (C')^2 ), where S' is a normalized saturation value in [0,1] from an HSV/HSL representation, and C' is a normalized chroma value in [0,1] from a perceptual space like CIELCh. Other formulations employ a weighted sum, SC = w1*S' + w2*C'. Normalization depends on the chosen maximums for saturation and chroma within a given color space, device, or viewing conditions.

Usage and interpretation

Saturationchroma can be used as a shorthand for comparing color vividness across hues and implementations, particularly in color grading, image processing, and perceptual color matching. It aims to provide a single descriptor of color intensity that accounts for both saturation and chroma. However, because saturation and chroma originate from different color representations and depend on illumination, viewing conditions, and device gamut, saturationchroma is a relative indicator rather than an absolute measure.

See also

Related concepts include saturation, chroma, colorfulness, and the L*a*b*/LCh color spaces.