摘要:
A method for marking a compressed digital video signal by embedding a digital signature in the compressed video signal, the signal representing a series of at least two video images, each image being divided into a plurality of regions, the signal including movement vectors representing the movement of the regions between the first and the second image, characterised in that it consists in modifying at least one of the coefficients X or Y of at least one of the movement vectors.
摘要:
The present application concerns the visual identification of materials or documents for tracking or authentication purposes.It describes methods to automatically authenticate an object by comparing some object images with reference images, the object images being characterized by the fact that visual elements used for comparison are non-disturbing for the naked eye. In some described approaches it provides the operator with visible features to locate the area to be imaged. It also proposes ways for real-time implementation enabling user friendly detection using mobile devices like smart phones.
摘要:
The present invention proposes a method for generating a security bi-level image used to form one of the inks of a banknote, said image comprising an original bi-level image and a security pattern, said security pattern being obtained in the spatial domain by the inverse Fourier transform of the combination in the frequency domain between the Fourier transform of an auxiliary image and a two-dimensional sweep, said two-dimensional sweep being a circularly symmetric, two-dimensional pattern created by sweeping a self-similar, one-dimensional function along a 360-degree arc, such as said security pattern being detectable from the maximum value of the cross-correlation of said one-dimensional function with the Fourier transform of one line of said banknote, said method comprising the step of: —determining a distance map of the original bi-level image, —generating a merged image by linearly interpolating at least a part of said distance map with said security pattern, —thresholding the merged image to obtain the security bi-level image, —applying the security bi-level image on a support.
摘要:
A method to authenticate genuine tablets manufactured by compressing powder between a punch/die set comprising the steps of: creating a microstructure on the surface of at least one of the face of the punch/die set; compressing the powder between the punch and the die; acquiring at least one reference image of the face of the punch/die set containing the microstructure or of a face of a tablet corresponding to the microstructure; acquiring at least one test image of a tablet to be authenticated; computing a level of similarity by an electronic device between the at least one test image and the at least one reference image; comparing the computed level with a threshold value so as to define if the acquired tablet is genuine.
摘要:
The invention describes a process to prevent counterfeiting or alteration of a printed or engraved surface, characterized by the incorporation of a signature of the form of a digital mark into parts or the entire document, and in particular a digital mark technology to hide information in an invisible way through over-printing by using a method called asymmetric amplitude modulation. This method can be applied to any type of printed material such paper, packaging, or any other surface. Visible information can also be printed over the digital mark. As an application example, applied to a paper document the digital mark can be used to guarantee the document authenticity, as it would be destroyed by a copy process.
摘要:
Example embodiments relate to a method for applying a special mark, that is invisible to the naked eye, on a medium. That is, the example embodiments provide a method for generating and applying on a medium a digital spatial mark of X×Y dots in accordance with a resolution of d1x by d1y dots per surface unit, provided that the ratio d1x/d2x and or d1y/d2y is more than 1. The method further includes over-sampling the digital spatial mark in X based on a factor nx=d1x/d2x and in Y based on a factor ny=d1y/d2y; eroding the dots to be applied so as to leave one dot every nx dots in X and one dot every nx dots in Y; and applying the spatial mark on the support.
摘要:
The present application concerns the visual identification of materials or documents for tracking or authentication purposes.It describes methods to automatically authenticate an object by comparing some object images with reference images, the object images being characterized by the fact that visual elements used for comparison are non-disturbing for the naked eye. In some described approaches it provides the operator with visible features to locate the area to be imaged. It also proposes ways for real-time implementation enabling user friendly detection using mobile devices like smart phones.
摘要:
The present invention aims to provide a simple and reliable security element into a document, which can be recognized without special equipment. This aim is achieved with a paper or paper-like document with a surface, the surface being provided at least in a partial area with a background layer, wherein at least part of the surface of the document is provided with a security element comprising a series of protuberant structures spaced at regular interval. The protuberant structure creates a relief than can be easily recognized while rubbing the document. Contrarily to watermarks or other stamps, the fact that the structure is spaced at regular interval allows the user to better detect it over random structures. Regular interval does not mean that the space between each protuberant structure is equal. Regular means that each structure has a similar width and each space between the structures has also a similar width.
摘要:
The present invention aims to propose a method to generate a security pattern to be embedded in an original image having the particularity that the detection of the security pattern can be achieved through a simple, low processing capability device. The present invention proposes a method for generating a security image comprising an original image and a security pattern, characterized in that the security pattern has the form of a grating in which the lines width and/or the line spacing is modulated to embody a predefined data, the security image is generated by the modulation of at least one color of at least a part of the original image with the grating. The present invention belongs to the fields of security printing and copy protection of banknotes. It aims at preventing illegal copy and duplication of banknotes by printing a security image on the banknote. A device capable of detecting this security image with one-dimensional signal processing is described. Acquisition and printing devices that contain this detector can perform a quick, on-the-fly analysis of the images that transit through them during their normal course of operations, and refuse to perform their function on an image if it contains the security image. This analysis is fast enough relatively to the normal operation of the device so as to go unnoticed by the user. The security image is incorporated by a bi-level halftone image. The Fourier transform of this halftone image contains a two-dimensional pattern with a circular symmetry that is built by applying a 360-degree rotation to a one-dimensional signal. This one-dimensional signal exhibits a degree of self-similarity across a given range of scale changes. It may be detected by traversing the two-dimensional pattern along a straight line passing through its center.
摘要:
The aim of this invention is to propose a process allowing the application of a spatial marking, that is to say invisible to the eye, on a support. A constraint consists in authorizing the reading of this marking by an acquisition apparatus of the image of a lower resolution. This aim is achieved by a generation and application process on a support of a digital spatial marking of X×Y points according to a resolution of d1x by d1y points per surface unit, and intended to be read by a reading device with resolution d2x by d2y points by surface unit, taking into account that the ratio d1x/d2x and/or d1y/d2y is larger than 1, this process comprising the following steps: sub-sampling of the digital spatial marking in X according to a factor nx=d1x/d2x and in Y according to a factor ny=d1y/d2y, erosion of the points intended to be applied so as to allow one point every nx points in X and a point every nx points in Y, application of the spatial marking on the support.