A printing method detects a density of a first black image to be printed in a first black color; determines, when the detected density is equal to a first density, a size of a first character to be embedded in the first black image to a first size, and prints the first character at the first size in a second black color with a transmissivity at a near infrared ray band that is different from that of the first black color; determines, when the detected density is lower than the first density, a size of the first character to a second size larger than the first size, and prints the first character at the second size in the second black color; and prints a region except a region in which the first character is to be printed in the first black image, in the first black color.

Correlation marks and gloss effect image patterns are created with vector-based electronic pattern inks. In creating a correlation mark, which is only visible by viewing the image through a reference screen, two vector-based electronic pattern inks are utilized to create the correlation mark, wherein the vector pattern in one electronic pattern ink is parallel, but out of phase, to the vector pattern in the other electronic pattern ink and the vectors of both electronic pattern inks are painted as thin lines. In creating a gloss effect, which is only visible by viewing the image at a predetermined angle, two vector-based electronic pattern inks are utilized to create the gloss effect, wherein the vector pattern in one electronic pattern ink is orthogonal to the vector pattern in the other electronic pattern ink and the vectors of both electronic pattern inks are painted as thick lines.

According to one embodiment, a nonvolatile semiconductor memory device includes a case, a memory in the case, a controller in the case. The controller controls the memory. First information including a determination code is printed on a surface of the case with invisible ink. Second information related to the nonvolatile semiconductor memory device is printed with visible ink which is visually recognizable in a visible light range.

The present invention relates to a protection system for printed documents using steganographic and computer vision, materialized by the use of portable devices, where ETCODE encoded images are generated for this purpose. This method was created in order to ensure the document's authenticity, integrity of information, store information about authorship and copyright protection of printed documents. The protection method described in this patent is to generate an encoded image ETCODE using steganographic techniques, to be printed with the document, using conventional printers, and also that the decoding is performed by a digital camera portable device, obtaining therefore the information hidden in ETCODE, and then confronted with the information about the document in its digital version present in a database, thus fulfilling the proposal document protection.

An image processing device includes circuitry configured to receive a first visible and an invisible image, remove the invisible component from the first visible image based on the invisible image to generate a second visible image, determine whether to remove the invisible component from the first visible image, and output either the first visible image based on a determination not to remove the invisible component or output the second visible image based on a determination to remove the invisible component. The first visible image is captured by a first sensor having a first sensitivity to both of first light in a visible wavelength range; and second light in an invisible wavelength range. The first visible image includes an invisible component in the invisible wavelength range. The invisible image is captured by a second sensor having a second sensitivity to the second light.