This thesis aims to solve an important scientific problem — to ensure the level of security of the printed documents, using the latent elements through the development of the information technology, which includes the methods for forming these elements and establishing their reliability.
The analysis of problems of the current document security state has been analyzed, which has revealed the need for the development of new methods and tools of graphic elements and the creation of effective specialized means of protection on their basis. The identification has been made to prevent violation of integrity and prevent document falsification. The methods and means of forming the latent images for controlling and detecting any distortions in documents have been developed. The construction of fine graphics based on the local distortions of the protective grid lines, changes in the thickness of the lines, contour filling and line separation has been carried out. In order to increase the level of the printed documents security, the use of fractal grids created in a vector format have been proposed. The models of image-based traps based on moire have been developed. The models become visible when copying by sticking and displacing lines in images, which ensures the creation of a high-quality secure document with consideration of conditions at the stage of forming a document for printing.
For the first time, information technology which includes methods for the formation of fine graphics, fractal and latent elements, the moire has been developed. The technology provides an increase in the identification of document originality. The identification has implemented the method of pixel comparisons of an original document and it copies. The methods of fine graphics formation, the formation of fractal protected elements, the creation of latent elements, the creation of moire for protection of documents against falsification have been developed in the dessertation.
The method for identifying a document for two numerical rational parameters of a line have been developed. The method allows reducing the amount of initial conditions input for determining the originality of the document and provides the reduction in the processing time of information. Moreover, the methodology of establishing document authenticity is implemented by constructing a generalized criterion. This criterion is based on the data obtained while using the measuring equipment of documents by the method of comparison with the standards.
The obtained methods give the opportunity to predict and identify falsification. The improvement of the information technology, which includes the methods for forming fine graphics, fractal elements, creating latent elements, forming moire, increased the effectiveness of detection areas of falsification. The use of new ways has increased the security and prevented interference with the document. The information characteristics of the printed document include optical density, raster point %, uniformity of ink application, compression, trapping, which were measured by special equipment on the originals and copies, and the criterion signs of threshold characteristics were deduced from them. The errors for originals and forged documents have been established based on the measured values. The developed methods provided practical recommendations regarding the provision of the appropriate level of printed documents identification and, have improved the reliability of the document which based on the analytical dependence of the original and a copy of the spectrophotometer removed by the indicators.
