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.

The present disclosure relates generally to signal encoding for printed objects. One implementation selects an embed direction based on a minimal visibility axis of a 1 JND ellipse at a certain color center. One claim recites an apparatus comprising: memory for storing chromatic contrast sensitivity data representing multiple color encoding angles; one or more multi-core processors configured for: using the stored chromatic contrast sensitivity data, generating an ellipse around a first color center; and from the ellipse, determining a signal encode direction, the signal encode direction comprising an angle α representing a negative angle between the ‘a*’ axis in an CIELAB space and a direction of minimum sensitivity of an encoded signal, in which the angle α comprises −9 degrees≥α≥−25 degrees. Other technology described.

An image processing method determines a geometric transform of a suspect image by efficiently evaluating a large number of geometric transform candidates in environments with limited processing resources. Processing resources are conserved by using complementary methods for determining a geometric transform of an embedded signal. One method excels at higher geometric distortion, and specifically, distortion caused by greater tilt angle of a camera. Another method excels at lower geometric distortion, for weaker signals. Together, the methods provide a more reliable detector of an embedded data signal in image across a larger range of distortion while making efficient use of limited processing resources in mobile devices.

The present invention generally relates to the field of automated and flexible information extraction and protection for graphical data. In particular, the invention provides a unique platform for analyzing, classifying, extracting, and processing information from images using deep learning image detection models. Embodiments of the inventions are configured to provide an end to end automated solution for intelligently hiding or obscuring private data from graphical displays via the use of embedded steganographic image data techniques.

This disclosure relates to advanced signal processing technology including signal encoding and digital watermarking. Image areas are selected in an encoded digital design, and corresponding areas from a printed version of the encoded digital design are evaluated to determined signal robustness after printing. One claim recites an image processing method for selecting image areas to test for robustness of encoded signals, the method comprising: obtaining digital artwork comprising a plurality of colors, the digital artwork comprising multiple instances of an encoded signal; selecting a set encoding tiles, and for each encoding tile determining encoding detectability measure associated therewith; creating a bin for each encoding technology used to encode the encoded signal; for each bin, removing any encoding tile having a detectability measure below a predetermined threshold; for each bin, prioritizing remaining encoding tiles; selecting an encoding tile based on the prioritization per bin, and spatially locating the selected encoding tile relative to the digital artwork. Other technology is described in this patent document.

Various features described herein may allow an authorized user to provide a guest with access to a secured location through use of an encoded image containing steganographically encoded access information. The encoded access information may be recognizable by a security system, and the security system may grant access to the secured location when the encoded image is presented to the security system. The authorized user may request the generation of the encoded image on an authorized computing device, and the encoded image may be provided to the guest on a guest computing device. When a monitoring device associated with the security system captures the encoded access information, the security system may, for example, open a door at the secured location.

Generation of one dimensional guilloche patterns able to be affixed on a document, each guilloche pattern being able to encode variable alphanumeric data providing a different appearance to each guilloche pattern, by formatting alphanumeric data to be encoded in the form of a predefined number of data blocks with a predefined size, generating a carrier function having a plurality of parameters, the formatted data blocks forming at least one of the parameters, and modulating the carrier function by the formatted data blocks so as to encode the alphanumeric data graphically, each data block defining a guilloche pattern, the number of data blocks defining the number of guilloche patterns, the carrier function associated with a formatted data block is modulated locally, each datum of the block being encoded locally in the guilloche pattern, by interpolation of a predefined point associated with the carrier function.

A method for inserting information into a first image including N1 rows×M1 columns of elements includes: a) obtaining, from the first image, a second image including N0 rows×M0 columns, N0 ≤N1 and M0≤M1, b) generating initial information including N0 rows×M0 columns, c) obtaining intermediate information including N4 rows×M4 columns of elements, so N4≥N1 and M4≥M1, and N4=kx.N0 and M4=ky.M0, kx and ky being integers≥1, the elements organized into blocks, d) obtaining information to be inserted from the intermediate information, including: generating symbols representing noise, including as many symbols as block elements, at least one <>0, so the result of a function applied to the symbols=a chosen value, adding each symbol to the corresponding block element, and e) inserting the obtained information into the first image.

The geometric pose of a patch of watermark data is estimated based on the position of a similar, but non-identical, patch of information within a data structure. The information in the data structure corresponds to a tiled array of calibration patterns that is sampled along at least three non-parallel paths. In a particular embodiment, the calibration patterns are sampled so that edges are globally-curved, yet locally-flat. Use of such information in the data structure enables enhanced pose estimation, e.g., speeding up operation, enabling pose estimation from smaller patches of watermark signals, and/or enabling pose estimation from weaker watermark signals. A great variety of other features and arrangements are also detailed.

Differential modulation schemes encode a data channel within host signal or noisy environment in a manner that is robust, flexible to achieve perceptual quality constraints, and provides improved data capacity. Differential arrangements enable a decoder to suppress host signal or other background signal interference when detecting, synchronizing and extracting an encoded data channel. They also enable the incorporation of implicit or explicit synchronization components, which are either formed from the data signal or are complementary to it.