Feature-based watermark localization in digital capture systems
AssigneeDigimarc Corporation
InventorsVojtech Holub, Tomas Filler
Life of this patent
Estimating the term…
Abstract
The present disclosures relates generally to digital watermarking and data hiding. One claim recites a method comprising: obtaining data representing captured imagery, the captured imagery depicting packaging including digital watermarking, the digital watermarking including an orientation signal that is detectable in a transform domain; generating a n-dimensional feature set of the data representing captured imagery, the n-dimensional feature set representing the captured imagery in a spatial domain, where n is an integer great than 13; using a trained classifier to predict the presence of the orientation signal in a transform domain from the feature set in the spatial domain. Of course, other claims and combinations are provided too.
Claims19
A method comprising:
- obtaining data representing optically captured imagery, the optically captured imagery depicting packaging including digital watermarking, the digital watermarking including an orientation signal that is detectable in a transform domain;
- generating an n-dimensional feature set of the data representing the optically captured imagery, the n-dimensional feature set representing the optically captured imagery in a spatial domain, where n is an integer greater than 13;
- using a trained classifier to predict the presence of the orientation signal in a transform domain from the feature set in the spatial domain.
An apparatus comprising:
- memory for buffering blocks of image data, the image data having been captured with a camera and depicting product packaging;
- one or more processors programmed for:
- generating a spatial domain feature set representation of a block of image data;
- applying a machine-trained classifier to predict from the spatial domain feature set whether the block of image data includes a transform domain digital watermark signal.
A method comprising:
- decomposing data representing an image into subcomponents;
- extracting predetermined features from each of the subcomponents;
- providing the features to a trained logistic regressor for estimating a probability of a presence of digital watermarking contained in each the subcomponents;
- generating a probability map relative to the image based on probabilities generated by the trained logistic regressor;
- and
- selecting n subcomponents from the probability map, where each of the selected n subcomponents has a probability exceeding a predetermined threshold, where n is a positive integer greater than 1.
A method comprising:
- training a binary classifier on a plurality of training samples such that the binary classifier can generalize and classify feature vectors containing digital watermarking or not;
- extracting a feature vector from each of a plurality of image areas;
- applying the binary classifier to each extracted feature vector to classify the likelihood of a presence of digital watermarking in each image area;
- and
- based on results of said act of applying, directing a digital watermark reader to consider image data from only a subset of the plurality of image areas.
Dependencies are inferred from the claim text.