A watermark generator for providing a watermark signal as a sequence of subsequent watermark coefficients based on a stream of subsequent stream values representing discrete valued data includes a differential encoder. The differential encoder is configured to apply a phase rotation to a current stream value of the stream values representing the discrete valued data or to a current watermark symbol, the current watermark symbol corresponding to a current stream value of the stream values representing the discrete valued data, to obtain a current watermark coefficient of the watermark signal. The differential encoder is configured to derive a phase of a previous spectral coefficient of a watermarked signal which is a combination of the host signal and the watermark signal, and to provide the watermark signal such that a phase angle of the phase rotation applied to the current stream value or the current watermark symbol is dependent on the phase of the previous spectral coefficient of the watermarked signal.

An information code image display system includes an area specifying part, an image generation part, and a display controller. The area specifying part specifies an area as a conversion target area, the area being a part of a base image displayed in a display area of a display part. The image generation part generates a base-image-attached information code image by applying an information code to a conversion target image corresponding to the conversion target area. The display controller displays in the display part the base-image-attached information code image and a remaining image obtained by excluding an image of the conversion target area from the base image.

The present invention relates generally to digital watermarking. One aspect of the disclosure includes a method comprising: obtaining data representing imagery; using one or more configured processors, analyzing a plurality of portions of the data to detect a watermark orientation component, said analyzing employing a match filter, in which the match filter yields a correlation value for each of the plurality of portions; determining a first portion from the plurality of portions that comprises a correlation value meeting a predetermined value; and directing a watermark decoder at the first portion to decode a plural-bit watermark payload, in which the watermark decoder produces a watermark signature for the first portion, and in which the watermark decoder searches a plurality of areas at or around the first portion to decode the plural-bit watermark payload. Of course, many other aspects and disclosure are provided in this patent document.

Watermark data is converted to watermark coefficients, which may be embedded in an image by converting the image to a frequency domain, embedding the watermark in image coefficients corresponding to medium-frequency components, and converting the modified coefficients to the spatial domain. The watermark data is extracted from the modified image by converting the modified image to a frequency domain, extracting the watermark coefficients from the image coefficients, and determining the watermark data from the watermark coefficients. The watermark data may be truncated image data bits such as truncated least significant data bits. After extraction from the watermark, the truncated image data bits may be combined with data bits representing the original image to increase the bit depth of the image. Watermark data may include audio data portions corresponding to a video frame, reference frames temporally proximate to a video frame, high-frequency content, sensor calibration information, or other image data.

A memory stores video information obtained by photographing an object that reflects light in which embedded information is superimposed onto a plurality of components in a color space. A processor emphasizes a signal obtained from an image included in the video information on the basis of a result of emphasizing a first color component more than a second color component according to a spectral reflection characteristic in a range including the object, and detects the embedded information from the emphasized signal, the first color component and the second color component being from among a plurality of color components that correspond to a plurality of wavelengths, the first color component having a reflectance higher than a reflectance of the second color component. A display device outputs information on the basis of the embedded information detected by the processor.

An image conversion method is provided for integrating a security feature in a digital source image to generate a target image secured by the integrated security feature. The image conversion method includes carrying out transverse-wave-shaped distortion of the source image to generate an intermediate image; generating a target image, the intermediate image being scanned by rows of pixels to define, per row of pixels of the intermediate image, a sequence of successive pixels according to the scanning, and each pixel of the sequence being transformed to a corresponding pixel of the target image. The arrangement of the respective pixels of each sequence is a transverse-wave-shaped wave packet in the target image; and the integrated security feature is defined by the wave packets.

A variety of methods and systems involving sensor-equipped portable devices, such as smartphones and tablet computers, are described. One particular embodiment decodes a digital watermark from imagery captured by the device and, by reference to watermark payload data, obtains salient point data corresponding to an object depicted in the imagery. Other embodiments obtain salient point data for an object through use of other technologies (e.g., NFC chips). The salient point data enables the device to interact with the object in a spatially-dependent manner. Many other features and arrangements are also detailed.

An information insertion method, an information extraction method, and an information extraction apparatus using dot-based information are provided herein. The information extraction apparatus includes an identification unit and an extraction unit. The identification unit identifies a set of at least one dot output to a target. The extraction unit extracts information from the set of at least one dot.

Methods are provided for encoding watermark information into media data containing a series of digital samples in a sample domain. The methods involve: dividing the series of digital samples into a plurality of sections in the sample domain, each section comprising a corresponding plurality of samples; processing the corresponding plurality of samples in each section to obtain a single energy value associated with each section; grouping the sections into groups, each group containing three or more sections; for each group, assigning a nominal bit value according to a bit assignment rule, assigning a watermark bit value and comparing the watermark bit value to the nominal bit value. If the nominal bit value and the watermark bit value do not match, modifying one or more energy values of one or more corresponding sections in the group where re-application of the bit assignment rule would assign the watermark bit value to the group.

The present application relates to a method for producing and authenticating unforgeable printable image comprising information color values and inference color values. The present application further provides for unforgeable printed images.