Patent ID: 8724168

Claim:
A method for updating a smoothness constrained cluster model for color control in a color management system, the method comprising: receiving a cluster model designed for a color marking device; analyzing a structure of said cluster model to identify a plurality of clusters defined therein, each of said clusters being identified by at least one centroid of an input color space of said color marking device, each cluster having an associated transform comprising a regression matrix that is associated with each of said plurality of clusters; and in response to a threshold event having occurred: identifying at least one critical cluster from said plurality of clusters; identifying at least one critical color from said critical cluster, wherein identifying said critical color comprises selecting, from among at least two color points belonging to said critical clusters, a subset of color points based on a selection criterion comprising at least one of: sensitivity of said transform at said critical color; a calculated distance of said critical color from a centroid of said critical cluster; and directionality of a vector of said critical color to said centroid; printing a selected number of patches in said critical color; obtaining any of: a color and smoothness measurements, from said printed patches; and updating said cluster model in response to any of: said color and smoothness measurements having deviated beyond a defined threshold, wherein updating said cluster model comprises any of: updating the transform associated with any of said clusters; redefining a total number of clusters in said cluster model; redefining a center of any of said clusters; and redefining a boundary of any of said clusters.