| Author(s) | Collection number | Pages | Download abstract | Download full text |
|---|---|---|---|---|
| Тарасов Н. А., Khamula O. H., Сорока Н. В. | № 1 (87) | 115-124 |
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Typical options for applying the traditional power raster transformation of the bright part of the printed image are considered, and on the basis of the Yule-Nielsen formula, the characteristics of the optical density, as well as the indicators of demodulation and contrast sensitivity of tone reproduction, are determined. Using the method of object-oriented programming in the MATLAB: Simulink package, a structural diagram of the model of the tone reproduction simulator of printed images is developed, with the help of which the calculation of the optical density is performed, the typical characteristics of rasterization are built, and the contrast sensitivity is established.
It follows from the results of simulated modeling that the typical gradation characteristics of rasterization look like convex curves and that their stretching occurs when the degree index decreases. It is also established that at the beginning of the light range, the characteristics of the optical density have a rather significant steepness and are slightly concave, lumped curves.
The large initial steepness of the optical density characteristic causes jumps in contrast sensitivity with initial values of 4.8 to 2.5 units, after which they become concave curves that lead to final values of 3.14 to 7.08 units. It should be noted that the presence of such jumps causes posterization – noticeable transitions that distort the image and therefore require additional filtering of the image.
Keywords: raster transformation, digital image, raster characteristics, contrast sensitivity, demodulation, modeling, optical density, simulator, tone reproduction evaluations.
doi: 10.32403/0554-4866-2024-1-87-106-114
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