{ % Starting stack: L, A, B % /!\ WARNING: The A and B components **MUST** be encoded % in the range [0, 1] before calling this function. % This is because the function assumes that the % A and B components are offset by a factor of 0.5 % in order to meet the range requirements of the % PDF specification. exch 0.5 sub exch 0.5 sub % Load L a and b into the stack 2 index 2 index 2 index % Compute f1 = ((0.3963377774 * a) + (0.2158037573 * b) + L)^3 0.2158037573 mul exch 0.3963377774 mul add add dup dup mul mul % Load L, a, and b into the stack 3 index 3 index 3 index % Compute f2 = ((-0.1055613458 * a) + (-0.0638541728 * b) + L)^3 -0.0638541728 mul exch -0.1055613458 mul add add dup dup mul mul % Load L, a, and b into the stack 4 index 4 index 4 index % Compute f3 = ((-0.0894841775 * a) + (-1.2914855480 * b) + L)^3 -1.2914855480 mul exch -0.0894841775 mul add add dup dup mul mul % Discard L, a, and b by rolling the stack and popping 6 3 roll pop pop pop % Load f1, f2, and f3 into the stack 2 index 2 index 2 index % Compute R = f1 * 4.0767416621 + f2 * -3.3077115913 + f3 * 0.2309699292 0.2309699292 mul exch -3.3077115913 mul add exch 4.0767416621 mul add % Load f1, f2, and f3 into the stack 3 index 3 index 3 index % Compute G = f1 * -1.2684380046 + f2 * 2.6097574011 + f3 * -0.3413193965 -0.3413193965 mul exch 2.6097574011 mul add exch -1.2684380046 mul add % Load f1, f2, and f3 into the stack 4 index 4 index 4 index % Compute B = f1 * -0.0041960863 + f2 * -0.7034186147 + f3 * 1.7076147010 1.7076147010 mul exch -0.7034186147 mul add exch -0.0041960863 mul add % Discard f1, f2, and f3 by rolling the stack and popping 6 3 roll pop pop pop }