A method of verifying an authenticity of a printed item includes: photographing the printed item to obtain a photographic image of the printed item, retrieving reference data of the printed item, the reference data including a reference image of the printed item, determining a test noise parameter from the photographic image of the printed item, determining a reference noise parameter from the reference image, comparing the test noise parameter of the photographic image of the printed item to the reference noise parameter of the reference image, and determining an authenticity of the printed item from a result of the comparing. The determining the authenticity of the printed item from the result of the comparing may include establishing from the reference noise parameter of the reference image and the test noise parameter of the printed item.

A method of verifying an authenticity of a printed item includes: photographing the printed item to obtain a photographic image of the printed item, retrieving reference data of the printed item, the reference data including a reference image of the printed item, determining a test noise parameter from the photographic image of the printed item, determining a reference noise parameter from the reference image, comparing the test noise parameter of the photographic image of the printed item to the reference noise parameter of the reference image, and determining an authenticity of the printed item from a result of the comparing. The determining the authenticity of the printed item from the result of the comparing may include establishing from the reference noise parameter of the reference image and the test noise parameter of the printed item.

A method of verifying an authenticity of a printed item includes: photographing the printed item to obtain a photographic image of the printed item, retrieving reference data of the printed item, the reference data including a reference image of the printed item, determining a test noise parameter from the photographic image of the printed item, determining a reference noise parameter from the reference image, comparing the test noise parameter of the photographic image of the printed item to the reference noise parameter of the reference image, and determining an authenticity of the printed item from a result of the comparing. The determining the authenticity of the printed item from the result of the comparing may include establishing from the reference noise parameter of the reference image and the test noise parameter of the printed item.

A combination of a latent-image pattern which forms a latent-image part and a background pattern that forms a background-image part is determined so that the latent-image part and background-image part have equal print densities. The determined latent-image pattern and background pattern, color information used to determine a color of the copy-forgery-inhibited pattern image, input image information as an image to be processed, copy-forgery-inhibited pattern basic information used to designate the latent-image part and background-image part, and camouflage region designation image information used to designate a camouflage region are input. A copy-forgery-inhibited pattern image is generated on the basis of the input information.

A combination of a latent-image pattern which forms a latent-image part and a background pattern that forms a background-image part is determined so that the latent-image part and background-image part have equal print densities. The determined latent-image pattern and background pattern, color information used to determine a color of the copy-forgery-inhibited pattern image, input image information as an image to be processed, copy-forgery-inhibited pattern basic information used to designate the latent-image part and background-image part, and camouflage region designation image information used to designate a camouflage region are input. A copy-forgery-inhibited pattern image is generated on the basis of the input information.

A method of verifying an authenticity of a printed item includes: photographing the printed item to obtain a photographic image of the printed item, retrieving reference data of the printed item, the reference data including a reference image of the printed item, determining a test noise parameter from the photographic image of the printed item, determining a reference noise parameter from the reference image, comparing the test noise parameter of the photographic image of the printed item to the reference noise parameter of the reference image, and determining an authenticity of the printed item from a result of the comparing. The determining the authenticity of the printed item from the result of the comparing may include establishing from the reference noise parameter of the reference image and the test noise parameter of the printed item.