LAB color is a mathematical 'mode' for handling color. Short for CIELAB, the LAB color system uses three measurements to describe a color: L for luminance, and A-B for a two-axis geometric position for the color inside a theoretical spherical space. LAB is useful to color management systems because its units of measure are perceptually equal, meaning that a 1-unit move in any direction within the sphere is visually equivalent to an equal move in any other direction. Images can be saved in LAB color from some scanners, and from some imaging software. Images saved in LAB require a preview file to be generated in RGB for the monitor, as LAB itself is not a visual model. |