Optical code signal components are generated and then transformed into signal bearing art that conveys machine readable data. The components of an optical code are optimized to achieve improved signal robustness, reliability, capacity and/or visual quality. An optimization program can determine spatial density, dot distance, dot size and signal component priority to optimize robustness. An optical code generator transforms tiles of an optical code or image embedded with the optical code into signal-bearing art using stipple, Voronoi, Delaunay or other graphic drawing methods so as to retain prioritized components of the optical code. The optical code is merged into a host image, such as imagery, text and graphics of a package or label, or it may be printed by itself, e.g., on an otherwise blank label or carton. A great number of other features and arrangements are also detailed.

Techniques are disclosed for rendering a watermark on content in a manner as to not obfuscate or otherwise cause visual defects to data elements in the content. An example methodology implementing the techniques includes segmenting a watermark to be rendered on the content into multiple watermark pieces. Then, prior to rendering a particular watermark piece, a check is made to determine whether there is a data element at the location in the content at which the particular watermark piece is to be rendered. If a data element is detected at that location, the particular watermark piece is rendered such that the data element overlays the particular watermark piece to render the watermark as a masked watermark. Otherwise, if no data element is detected at that location, the watermark piece is rendered on the content to be visible. The process is repeated to render the remaining watermark pieces.

A printing system receives a print request containing patterns of marks to be printed on print media to produce printed output. A processor evaluates the print request to identify non-marking areas and identify different printing densities of the patterns of marks. The processor alters the patterns of marks to create hidden features on the printed output by adding a uniform printed background to the non-marking areas and adding different printing densities of fluorescent spots to different areas of the patterns of marks. The different printing densities of the fluorescent spots are based on the different printing densities of the patterns of marks and on the size of the hidden features. A printing device prints the print request on the print media to produce the printed output.

Provided is a method of embedding and extracting watermark data that is robust against geometric distortion and low-quality photographing and for which the probability of successfully extracting watermark data for an original image is high, while the probability of successfully extracting the watermark data in the case of unauthorized copying is seriously impaired. The data embedding method according to an embodiment of the present invention comprises a step of converting the noise-based image using watermark data, and a step of adjusting the original image using the converted noise-based image.

Provided is a method of embedding and extracting watermark data that is robust against geometric distortion and low-quality photographing and for which the probability of successfully extracting watermark data for an original image is high, while the probability of successfully extracting the watermark data in the case of unauthorized copying is seriously impaired. The data embedding method according to an embodiment of the present invention comprises a step of converting the noise-based image using watermark data, and a step of adjusting the original image using the converted noise-based image.

Provided is a method of embedding and extracting watermark data that is robust against geometric distortion and low-quality photographing and for which the probability of successfully extracting watermark data for an original image is high, while the probability of successfully extracting the watermark data in the case of unauthorized copying is seriously impaired. The data embedding method according to an embodiment of the present invention comprises a step of converting the noise-based image using watermark data, and a step of adjusting the original image using the converted noise-based image.

Provided is a method of embedding and extracting watermark data that is robust against geometric distortion and low-quality photographing and for which the probability of successfully extracting watermark data for an original image is high, while the probability of successfully extracting the watermark data in the case of unauthorized copying is seriously impaired. The data embedding method according to an embodiment of the present invention comprises a step of converting the noise-based image using watermark data, and a step of adjusting the original image using the converted noise-based image.

To generate a security mark, a system prints first and second patterns on a first document using non-infrared absorbing colors. A print engine will receive the substrate and create a copy of the security mark onto a second document. When printing the second document the print engine may use ink of an infrared-absorbing color, such as black, to print a hidden security element of the security mark. When an infrared camera captures a digital image of the second document and the captured image is displayed, the captured image will reveal the hidden security element.

A method and system for rendering a gloss effect image on a recording medium, can involve creating with a processor, a mirror of a gloss effect image of a gloss mark located on a front side of a recording medium, and rendering with a color printer having marking materials, the mirror of the gloss effect image on a back side of the recording medium directly opposite the gloss mark located on the front side of the recording medium. The processor can include a digital front processor that communicates with the color printer. The gloss effect image of the gloss mark can be, for example, a micro gloss feature or a macro gloss feature.

In one embodiment, a method for 3D digital watermarking for a triangular mesh using one or more key parameters is disclosed including forming a Hamiltonian path of a desired length around a selected vertex in a selected direction of a spiral; marking the selected vertex a dead end if there is a deadlock and continuing the spiral; and applying a watermark by introducing points in a path order on edges of the spiral, wherein information is encoded at a partition of adjacent triangles at one or more of the points.