Correspondence Between CIELAB and CIELUV Color Differences

The CIE presently recommends two uniform color spaces, the CIE 1976 (L*u*v*)‐space (CIELUV) and the CIE 1976 (L*a*b*)‐space (CIELAB). With each of these spaces is associated a color‐difference formula. Color differences calculated by one formula cannot readily be converted to color differences calculated by the other formula. A conversion factor such as ρ = ΔE uv */ΔE ab * cannot be determined uniquely. However, for any given location in color space, it is possible to determine a range, ρ min ⩽ ρ ⩽ ρ max , within which ρ must lie. Lines of constant ρ min and ρ max can be plotted in (L*a*b*)‐space which indicate the range of ρ in (L*u*v*)‐space.