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In response to the ever increasing need for new anticounterfeiting methods, a new integrated print-based authentication and security strategy is proposed for the protection of valuable documents and products, based on moire intensity profiles. This strateg ...
We present some issues that arise when a geometric transformation is performed on an image or a volume. In particular, we illustrate the well-known problems of blocking, blurring, aliasing and ringing. Although the solution to these problems is trivial in ...
We present an automatic sub-pixel registration algorithm that minimizes the mean square difference of intensities between a reference and a test data set, which can be either tri-dimensional (3-D) volumes or bi-dimensional (2-D) images. It uses spline proc ...
"Symmetry is a complexity-reducing concept [...]; seek it every-where." - Alan J. Perlis Many natural and man-made objects exhibit significant symmetries or contain repeated substructures. This paper presents a new algorithm that processes geometric models ...
Daughter crystals in orientation relationship with a parent crystal are called variants. They can be created by a structural phase transition (Landau or reconstructive), by twinning or by precipitation. Internal and external classes of transformations defi ...
We present diffractive second-line security features based on the moire phenomenon, that are designed for use in Optically Variable Devices (OVDs). After a short introduction of our 2D and 1D moire methods, we first present the integration of line-based, 1 ...
International Society for Optical Engineering, Bellingham WA, WA 98227-0010, United States2006
This paper presents a distributed algorithm for the detection of patterns or their transformed versions, in noisy images. The proposed method projects the observed signal onto a redundant and structured dictionary of functions, which are distributed among ...
The best method for investigating moiré phenomena in the superposition of periodic layers is based on the Fourier approach. However, superposition moiré effects are not limited to periodic layers, and they also occur between repetitive struct ...
The disclosed method and system may be used for creating advanced protection means for various categories of documents (e.g. bank notes, identity documents, certificates, checks, diploma, travel documents, tickets) and valuable products (e.g. optical disks ...
Moire phenomena of different types are frequently encountered in electronic imaging. Most common are moire effects that occur between periodic structures. These effects have been intensively investigated in the past, and their mathematical theory is today ...
