System and method for characterizing color separation misregistration

A color separation misregistration characterization system, comprising:

• a tangible processor for receiving a colorimetric value corresponding to a colorimetric measurement of respective marked patches of plurality of marked patches included in an output image output by a printer device using color separations of a color space for marking a substrate, wherein the plurality of patches includes at least one pair of patch series, each pair of patch series including a first and second series of patches, each patch of the plurality of marked patches having markings of a first and second color separation, wherein:
• the markings include parallel lines including lines of the first color separation and lines of the second color separation, wherein the parallel lines of the second patch series are oriented at an angle relative to the parallel lines of the first patch series, wherein the relative angle is not an integer multiple of 180 degrees;
• and
• the lines of the first color separation have different incremental displacements relative to the lines of the second color separation for each respective patch of a series of patches of the at least one series of patches;
• the processor comprising:
• a phase lag analysis module including a series of programmable instructions executable by the processor for:
• characterizing misregistration of the first color separation relative to the second color separation for both a fast and slow scan direction, wherein the fast scan direction is a direction of relative movement between a substrate and a device for transferring the color separations to the substrate, and the slow scan direction is a direction perpendicular to the fast direction, wherein the characterization of the misregistration for each of the fast and slow directions uses both the first and second patch series.

A method for characterizing color separation misregistration associated with marking a substrate, the method comprising:

• providing an input image having a plurality of patches including at least one series of patches, each patch having a pattern using a first and second color, wherein:
• the pattern of each patch of the input image includes a plurality of parallel lines including at least one line of the first color and at least one line of the second color;
• and
• the lines of the first color have different incremental displacements relative to the lines of the second color for each respective patch of a series of patches of the at least one series of patches;
• marking a substrate with a copy of the input image using a first and second color separation to correspond to the first and second colors, respectively;
• measuring color characteristic of markings of respective copied patches of the copied plurality of patches and generating corresponding colorimetric values;
• fitting a single curve to the received colorimetric values associated with each of the patches of the plurality of patches;
• determining a peak of the curve;
• determining a magnitude of the displacement that corresponds to the peak;
• characterizing misregistration of the first color separation markings relative to the second color separation markings based on the measured calorimetric values and the determined displacement magnitude;
• and
• determining an offset between the determined displacement magnitude and an expected displacement magnitude corresponding to an expected peak colorimetric value associated with ideal color separation registration;
• wherein the characterizing of the misregistration is further based on the determined offset.