Modelling of raster scale lineature impact on optical density

The methodological basis of the study is the basis of the image raster transformation associated with tone transfer and demodulation of rasterization. To solve this problem, methods of transformation of signals and images, their reproduction by printing means, mathematical modelling theory for demodulation of raster transformation – object-oriented programming in Matlab: Simulink application package have been used for designing a structural scheme of a model for demodulation of raster transformation and constructing a graduation characteristic of a linear raster scale for different lineatures. In the study, an imitation demodulation model has been developed to determine the optical density of a linear raster scale of various lineatures, provided that the die optical density is constant. The simulation of the demodulation process is carried out by the corresponding change in the area of the raster elements provided that the ink thickness on the surface of the raster printing elements throughout the interval of tone transfer is constant. The structural scheme of the linear raster scale demodulation model in the Matlab: Simulink application has been constructed and processed, which makes it possible to calculate and design the characteristics of demodulation of the linear raster scale for different lineatures. The results of the imitation modelling have been presented in the form of graduation characteristics of demodulation, which are not linear curves whose curvature depends on the lineature. The scientific novelty of the obtained results is that for the first time a simulation model of demodulation of a raster transformation has been constructed, which enables to design gradation characteristics of the raster scale demodulation, and their properties have been analyzed. The simulator of the raster transformation demodulation has been constructed, which allows to calculate and design gradation characteristics of demodulation at the stage of rasterization preparation in order to improve the accuracy of the model of the raster transformation demodulation.