| 摘要 |
PURPOSE:To identify an offset color printing from a gravure printing, and other printings by providing a picture scanning means, a power spectrum arithmetic means, an arrangement direction detecting means, a direction comparison means, or a correlation arithmetic means, etc. CONSTITUTION:Two color primary components in a color picture 1 are scanned with a picture scanner 3 through a color separation optical system 2, and through a picture memory 4, and a power spectrum arithmetic means 5, etc., a power spectrum picture is outputted to an arrangement direction detecting means 7. The means 7 detects the dot arrangement direction of each color primary component from an input picture signal, and outputs it to a direction comparison means 8. The means 8 performs the identification for a color printing method by discriminating a difference in the dot arrangement directions of the color primary components. Also, after scanning the color picture, the color printing method can be identified by discriminating the difference in the color primary components in dot string directions from the correlation values of picture element values among picture elements of color primary signals obtained through a delay means 9, and a correlation arithmetic means 10, etc. In other words, the color offset printing is identified from the gravure printing, etc. |
