OSA-UCS

In colorimetry the OSA-UCS (Optical Society of America Uniform Color Space) is a color space first published in 1947 and developed by the Optical Society of America’s Committee on Uniform Color Scales. Previously created color order systems, such as the Munsell color system, failed to represent perceptual uniformity in all directions. The committee decided that, in order to accurately represent uniform color differences in each direction, a new shape of three dimensional cartesian geometry would need to be used.

History and Development

The development of the OSA-UCS took place during many years, from 1947-1977. Not long after the first mathematical color model was developed by the CIE, David MacAdam showed that when selecting a color on the CIE chromaticity diagram, it could not be guaranteed that colors of the same perceived color difference around this color were at the same color distance with respect to the reference color. More simply, the Euclidean distance between any two colors on the chromaticity diagram could not be used as a uniform measure of perceived color difference. Immediately following this discovery work began to create a space that would behave uniformly in all directions of color difference.