Editing CIELAB color space (section)

{{short description|Standard color space with color-opponent values}}
{{Technical|date=November 2010}}
[[File:CIELAB color space top view.png|thumb|right|[[Color#Optimal_colors|Optimal colors]] (theoretical maximum chroma of surfaces) point cloud in CIE Lab, top view]]
[[File:CIELAB color space front view.png|thumb|right|[[Color#Optimal_colors|Optimal colors]] point cloud in CIE Lab, left view]]
[[File:Lab color space.png|thumb|right|The CIE 1976 (''L''*, ''a''*, ''b''*) color space (CIELAB), showing only colors that fit within the [[sRGB]] gamut (and can therefore be displayed on a typical computer display).  Each axis of each square ranges from −128 to 127.]]

The '''CIELAB color space''', also referred to as '''''L*a*b*''''', is a [[color space]] defined by the [[International Commission on Illumination]] (abbreviated CIE) in 1976.{{efn|Referring to CIELAB as "Lab" without asterisks should be avoided to prevent confusion with [[Hunter Lab]].}} It expresses color as three values: ''L*'' for perceptual lightness and ''a*'' and ''b*'' for the four [[Unique hues|unique colors]] of human vision: red, green, blue and yellow.  CIELAB was intended as a [[perceptually uniform]] space, where a given numerical change corresponds to a similar perceived change in color. While the LAB space is not truly perceptually uniform, it nevertheless is useful in industry for detecting small differences in color.

Like the [[CIE 1931 color space|CIEXYZ]] space it derives from, CIELAB color space is a device-independent, "standard observer" model. The colors it defines are not relative to any particular device such as a computer monitor or a printer, but instead relate to the [[CIE 1931 color space#CIE standard observer|CIE standard observer]] which is an averaging of the results of color matching experiments under laboratory conditions.