A color shift security feature is provided. In at least one form, a clear colorant is used to add content to a document to provide a visual indication if the document is printed on a printer with self-limiting behavior. In this manner, in at least one form, it can be determined if a document is authentic, secure and/or authorized.

A reading device includes a light source, an imaging element, a controller, a correcting unit, and a notifying unit. The light source is configured to irradiate an object with light. The imaging element is configured to receive and read the light from the object. The controller is configured to control a second reading operation of reading the object with an invisible image. The correcting unit is configured to perform correction with respect to the invisible image. The notifying unit is configured to notify an outside of at least the invisible image corrected.

A document determination system includes a server device that stores identification information in association with document information, a printer that prints a document image corresponding to the document information and a code image indicating the identification information on a print medium to generate a normal printed matter, and a scanner that reads a print image printed on a printed matter including the normal printed matter and a copied printed matter obtained by copying the normal printed matter. The printer prints the code image in a preset end region of the print medium. The server device determines whether the printed matter is the normal printed matter based on the code image included in the print image read by the scanner.

An image forming apparatus includes: an image processor that performs predetermined processing on image data; and an image former that forms an image of the image data that has been subjected to the predetermined processing, in which the image processor: includes a file memory; when image data has a low resolution, stores the image data in the file memory, and performs detection processing of detecting whether a predetermined pattern is contained on the image data; and when image data has a high resolution, performs resolution processing of converting the image data to have a predetermined resolution in parallel with binarization processing, and performs the detection processing on the image data.

An image forming apparatus that determines whether an image having coincidence with a registered image is included in an input image and controls execution of a job that uses the input image based on a result of the determination. The image forming apparatus includes an input unit that inputs a first image as a candidate of the registered image, an evaluation unit that evaluates whether the first image is suitable for use in the determination, and a control unit registers the first image as the registered image if the evaluation unit evaluates that the first image is suitable for use in the determination, and prevents the first image from being registered as the registered image if the evaluation unit evaluates that the first image is unsuitable for use in the determination.

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.

An image forming apparatus includes circuitry that binarizes image data, a memory, and a print engine unit that forms an image of the binarized image data. When the image data is low in resolution, the circuitry has the image data stored in the memory and thereafter performs on the image data, detection processing for detecting whether or not the image data includes a predetermined pattern before binarization processing. When the image data is high in resolution, the circuitry binarizes the image data, thereafter has the image data stored in the memory, thereafter further performs multivalue converting processing on the image data, and thereafter performs detection processing.

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.

An image forming apparatus has an image reading portion generating document image data, a job execution portion executing a job based on the document image data, a control portion controlling the job execution portion, and a storage portion storing a registered signature image. The control portion determines the degree of match between a document signature image present in the document image data and the registered signature image. The control portion permits execution of the job when the degree of match is equal to or higher than a first threshold value and inhibits execution of the job when the degree of match is lower than the first threshold value.

An information processing apparatus includes a setting unit, a detector and a controller. The setting unit sets setting information associating a registered image obtained by reading an image with control information indicating whether input image data is to be stored or not. The detector detects the registered image from the input image data. The controller controls whether or not the input image data including the registered image is stored in a storage based on the setting information.