Patent ID: 8681384

Claim:
An image processing apparatus, comprising: a first generating device which generates a first ground pattern comprising a vanishing image which can be perceived with naked eyes in an original but no portion of which can be perceived with naked eyes in a reproduction of the original to be obtained by an image forming apparatus; a second generating device which generates a second ground pattern comprising a latent image no portion of which can be perceived with naked eyes in the original but which can be perceived with naked eyes in the reproduction of the original, wherein a resolution lower than the read resolution is set to the latent image, and wherein the second ground pattern further includes a second visible pattern of a resolution higher than the read resolution; a synthesizer which synthesizes the first ground pattern and the second ground pattern, wherein the first ground pattern overlaps at least a portion, but not all, of the second ground pattern and the second ground pattern overlaps at least a portion, but not all, of the first ground pattern in a synthesized image; and a print data creator which creates print data for the image forming apparatus, the print data comprising an image of the original, the first ground pattern and the second ground pattern synthesized by said synthesizer into a single image for a page of a print data original, wherein the image forming apparatus has a ground color removal function, and a color in the first ground pattern is a around color to be removed by the ground color removal function, whereby the first ground pattern is caused to vanish in the reproduction of the print data original not completely due to the resolution limit of the image forming apparatus but by the function of removing the ground color to prevent appearance of an image composed of the ground color in the back side of the print data original, a color or a stain composed of the ground color in the print data original.