Patent ID: 8149459

Claim:
A method for mapping an out-of-gamut color to a surface of a color gamut, the method comprising: identifying a point x c in L*a*b* space having {L* c , a* c , b* c } values, said point x c being outside a boundary surface of a color gamut of a color marking device; identifying a point x 0 in L*a*b* space having {L* 0 , a* 0 , b* 0 } values, said point x 0 being inside said boundary surface of said color gamut; tracing a ray between points x c and x 0 , said ray intersecting said boundary surface of said color gamut at intersection point x b ; dividing said ray into a plurality of discrete points, each discrete point x i having {L* i , a* i , b* i } values, where i is an index of a current point; setting a threshold error to a default value; repeating, for each of said discrete points, for a defined number of iterations to be performed on current point x i , until an intersection of said ray with said boundary surface of said gamut has been detected: determining an amount of a deltaE color separation between L*a*b* output values obtained on a previous iteration and {L* i , a* i , b* i } values of current point x i ; and comparing said deltaE color separation with said threshold error, in response to said deltaE color separation being greater than said threshold error, said intersection having not been detected, further comprising: processing said deltaE color separation with N-color values obtained on a previous iteration to generate new N-color values for the current iteration, where N≧3; and obtaining new L*a*b* output values using said new N-color values as inputs; and in response to said intersection having been detected, providing said {L* b , a* b , b* b } values of intersection point x b to a gamut mapping function, point x b being current point x i .