METHOD AND APPARATUS FOR JUDGING SURFACE

PURPOSE: To determine surface coating in multi color printing by performing measurement only for a printing color where reflection spectral characteristics are not the same as the combination reflection spectral characteristics of an arbitrary overlapped printing of other printing colors. CONSTITUTION: Reflection dispersion in a measurement segment 1 on a printing material surface 2 is measured photoelectrically by a color measurement head 3 via an objective lens 4. Then, seven color separation images can be created by utilizing a color screening sensor field 7 via the lens 4 from the segment 1. The sensor 7 creates a clear image at a sensor field for separating each color. For example, the degree of the surface coating of black color is performed by a two-step image analysis by three color separation image processings in an image analysis system 8. The system 8 consists of a host computer 9 and individual processing stage is displayed on a color image monitor 10.