THE HOLOGRAPHIC APPROACH TO EMBEDDING THE LATENT WATER MARKS IN THE PHOTOS

The counteraction to methods of a fake and falsification paper, and recently and plastic documents is a traditional and urgent task of protection of carriers of the information. One of key elements of many documents is the photo. Among such documents it is possible to name the passports, driver's certificates, medical policies, bank credit and identification cards. The economic and legal damage, which is put by a fake of the official documents, is huge and accrues avalanchely.

Now new methods and means of protection based on last achievement of physics, chemistry, microelectronics intensively are developed. However, despite of a high level of development, the conceptual approach has serious lack, which is characterized by absence of conditional dependence between event of substitution of object of identification (photo of the document owner) and presence of a means of protection (for example, protective optical hologram).

The technology, offered us, provides association of object of identification and means of protection (latent water mark (WM)) in a single unit. In a photo of the owner of the document are built latent WM, i.e. information allowing to identify an image of the owner at a stage of check of the document. The event of substitution of object of identification becomes conditional dependent concerning a means of protection. Thus, reaction to substitution of a photo will be the conclusion about a fake of the document. Thus, fact of introduction of the information is latent.

In the report the holographic approach to embedding latent digital WM in a photo is stated. The physical interpretation of processes of embedding and visualization latent WM is given. Is established, that without dependence from what area, spatial or frequency, the embedding WM is carried out in, in a basis of these methods lays interference between a wave field, absent-minded WM and spatial carrying. The process of restoration of object is accompanied by occurrence of the real and imaginary image. Also is established, that the spectral signals WM should satisfy to a condition of bandlimitedness, i.e. to be Hilbert signals. In this case, the real and imaginary components of the complex hologram WM are connected among themselves by transformation Hilbert. For embedding WM it is enough to calculate either only real, or only to imaginary component of the hologram. Accordingly, for restoration WM from the hologram it is enough to receive either only real, or only imaginary part of transformation Fourier of the complex hologram.

The positive experience of successful application of photographic carriers for record of the optical holograms proves expediency and availability of practical use latent WM for protection of photos. The holographic approach provides effective parametrical management of processes of creation, embedding and extraction WM.