Modulation of dyeing of rister-converted digital images of dark tonesv

A model of typical variants of raster-converted digital images of dark tones, their coloring, and gradation characteristics and sensitivity were developed. A structural diagram of a simulator model of coloring of raster-converted digital images of dark tones was constructed in the MATLAB:Simulink package, which simultaneously calculates and builds the characteristics of rasterization, performs their coloring, calculates and creates gradation characteristics of typical variants of raster-converted digital images and contrast sensitivity. The results of simulation modeling are presented. The characteristics of typical variants of raster-converted digital images were constructed. It is established that at the power index r=1.0 the rasterization characteristic is linear and corresponds to the rasterization of a linear raster scale. When the power index decreases, the characteristics are convex curves, stretched towards dark tones. The presented results of modeling the characteristics of raster transformation of typical variants of digital images of dark tones are convex curves, have a small initial steepness, which gradually increases. The rasterization characteristics are evenly stretched towards dark tones. The raster transformation tinting graphs at the tinting coefficient Kv=1 correspond to the rasterization characteristics.

The graphs of the gradation characteristics of raster transformation of typical variants of digital images have initial values of 255 levels and are convex curves evenly stretched towards dark tones. The initial steepness of the characteristics is small and gradually increases, and at the end of the range is quite large. By reducing the power index r, it is possible to form different gradation characteristics of raster-transformed colored digital images, which expands the functionality of preparing images for printing.

It has been established that the contrast sensitivity is negative. The initial sensitivity values: -1.0; -0.75; -0.48; -0.34 units, gradually decreasing, in light tones in the vicinity of L0≥230 they turn into convex curves with great steepness and at the end of the range are: C1=-1.0; C2=-1.95; C3=-3.82; C4=-6.4 units. Contrast sensitivity characterizes the sensitivity of the human eye to the perception of images, it is the greatest in light areas. The contrast sensitivity of colored raster-transformed digital images has been determined, which is a negative value and characterizes the perception of the image by the human visual system.

Keywords: model, raster conversion, digital image, colorization, simulator, rasterization characteristics, rasterization properties.

doi: 10.32403/0554-4866-2024-2-88-41-49