Lab color space

A Lab color space is a color-opponent space with dimension L for lightness and a and b for the color-opponent dimensions, based on nonlinearly compressed (e.g. CIE XYZ color space) coordinates. The terminology originates from the three dimensions of the Hunter 1948 color space, which are L, a, and b. However, Lab is now more often used as an informal abbreviation for the L-a-b representation of the CIE 1976 color space (or CIELAB, described below). The difference between the original Hunter and CIE color coordinates is that the CIE coordinates are based on a cube root transformation of the color data, while the Hunter coordinates are based on a square root transformation. Other examples of color spaces with Lab representations include the CIE 1994 color space and the CIE 2000 color space.