Patent ID: 7596261

Claim:
A method of metrologically detecting differences in a visually perceived color impression between a multi-color patterned surface of a reference surface and a multi-color patterned surface of an item under test, comprising the steps of: detecting a surface of the item under test and obtaining captured signals from the detected surface, said captured signals comprising signals produced by an image rendering sensor provided with color capability which scans at least a section of the item under test; obtaining a description of color characteristics of the multi-color patterned surface from the captured signals; concomitantly obtaining from the captured signals a description of picture definition of the multi-color patterned surface; obtaining a color characteristics variation rate by comparing the description of color characteristics with stored corresponding values of the reference surface; obtaining a picture definition variation rate by comparing the description of picture definition with corresponding stored values of the reference surface; and evaluating the visually perceived differences in color impression from the color characteristics variation-rate and the picture definition variation rate.