The present disclosure relates generally to signal encoding for elements within PDF files. One implementation encodes an artwork element under different encoding conditions, and selects a winner version based on resulting signal robustness and/or visibility. Other implementations generate PDF layer masks to help determine overall embedding robustness, including interference from layered elements. Other implementations are provided too.

Vision sensor dynamic watermarking via noise characterization are disclosed herein. An example device can capture an image by a first device, where the image comprising a pixel group has baseline noise characterization caused by a base noise profile for the first device. The device can produce a noise watermark to create a watermarked image, where the noise watermark can be produced by altering the baseline noise characterization to produce modified noise characterization. The device can also transmit the watermarked image to a receiver.

This disclosure relates to image signal processing technology including signal encoding. One claim recites a method of detecting plural-bit code conflicts within an image, the image includes at least one color separation. The image includes a first plural-bit code carried by a first symbology, and a second plural-bit code carried by a second symbology, the first symbology and the second symbology comprising different symbology types. The method includes: accessing a subset of the image that comprises the first plural-bit code carried by the first symbology; analyzing the subset of the image to decode the first plural-bit code; analyzing the at least one color separation to spatially locate and decode the second plural-bit code carried by the second symbology; comparing the first plural-bit code and the second plural-bit code; and outputting information if a conflict is identified by said act of comparing, in which the information comprises a spatial location within the image of the conflict. Of course, other claims, features and combinations are described as well.

An image forgery protection apparatus comprises: one or more memories; and circuitry. The circuitry generates challenge data which change with lapse of time at least in a predetermined period. The circuitry generates a unique response which changes with lapse of time, the unique response corresponding to the challenge data on a basis of a physically unclonable function. The circuitry changes subject image data correspondingly to the unique response, the subject image data obtained by capturing an image of a subject.

The present disclosure a method of providing identification code insertion service for tracking a duplicated image, which is performed by a server, including: (a) receiving an image from a user terminal; (b) converting the received image to black and white, and selecting a plurality of insertion regions in the converted image; (c) transforming an image of at least one of a plurality of insertion regions selected at random; and (d) mapping an identification code and image information included in the transformed image of the insertion region, storing the identification code and the image information in a database, and providing the image in which the identification code is inserted to the user terminal.

One aspect of the present invention discloses a watermark insertion method. The method includes: segmenting target text into pieces of page content; obtaining a watermark variable comprising a line alternation value indicative of a watermark mode changed for each line of the segmented page content and a watermark mode setting value; and applying a flip-flop component insertion algorithm for inserting a watermark into each of the pieces of segmented page content based on the obtained watermark variable.

A method, computer system, and a computer program product for image protection are provided. A first device includes a computer and a first camera. The first device identifies a picture that has a hallmark. The first device transmits a message requesting authorization to have a copy of the picture. The message contains data representative of the hallmark. The first device receives a response message. The first device determines whether the response message authorizes capture of a copy of the picture.

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.

Methods, devices, systems and computer program products are provided for embedding and detection of a watermark message to and from an object-based composite content. One exemplary method includes for embedding a watermark message in an object-based composite content includes designating a plurality of content objects for carrying the watermark message comprising one or more watermark symbols in the composite object-based content that is generated according to an object-based encoding scheme. The method also includes obtaining a mapping of each watermark symbol to a temporal or spatial position of one or more of the designated content objects in the composite content, and embedding each watermark symbol by including each of the one or more of the designated content objects in the composite content in conformance with the temporal or spatial relationship provided by the mapping.

A monochrome imager used in such systems as a scanner can detect watermarks that have been encoded in the color space or chrominance. Such watermarks are called chroma watermarks and are considered more reliable than the traditional classic watermarks, which are encoded based on luminance. The monochrome imager detects the chroma watermark, which has been illuminated with ambient white light from a blue light emitting diode (LED) coated with phosphor.