## 1 Introduction
\begin{table}
\begin{tabular}{c c c c c} \hline
**Operating Mode** & **Total Number of** & **Total Number of** & **Pixel Frequency** & **Horizontal Sync** \\
**of Display** & **Image Lines** & **Pixels in Line** & **[MHz]** & **Frequency** \\ \hline
640 \(\times\) 480/60 Hz & 525 & 800 & 25.175 & 31.469 \\ \hline
800 \(\times\) 600/60 Hz & 628 & 1056 & 40.000 & 37.789 \\ \hline
1024 \(\times\) 768/60 Hz & 806 & 1344 & 65.000 & 48.363 \\ \hline
1280 \(\times\) 1024/60 Hz & 1066 & 1688 & 108.000 & 63.981 \\ \hline
1366 \(\times\) 768/60 Hz & 798 & 1792 & 85.500 & 47.712 \\ \hline
1440 \(\times\) 900/60 Hz & 934 & 1904 & 106.500 & 55.935 \\ \hline
1600 \(\times\) 900/60 Hz & 1000 & 1800 & 108.000 & 60.000 \\ \hline
1600 \(\times\) 1200/60 Hz & 1250 & 2160 & 162.000 & 75.000 \\ \hline
1920 \(\times\) 1080/60 Hz & 1125 & 2200 & 148.500 & 67.500 \\ \hline
2048 \(\times\) 1152/60 Hz & 1200 & 2250 & 162.000 & 72.000 \\ \hline
4096 \(\times\) 2160/60 Hz & 2222 & 4176 & 556.744 & 133.320 \\ \hline \end{tabular}
\end{table} 
Table 1: Catalog parameter values of the rasterization for selected monitor operating modes (Data from [7]). raster parameters for data in graphic form [17; 18; 19]. It should not be forgotten that the revealing emission signals are very noisy signals and the images reproduced on their basis often contain only the outlines of the data sought. This is the result of the use of various solutions counteracting the effectiveness of the electromagnetic infiltration process, including in the form of electromagnetic screens [20] or noise generators [21]. Then, the accuracy of the aforementioned rastering parameters is very important, for example, for the successful use of coherent image summation algorithms, the result of which will be an improving the image quality and the readability of the data contained therein. Determining the signal raster parameters on the basis of catalog data or the results of previous measurements of analogous IT devices may be burdened with an error, preventing the reproduction of the image in a way that allows for unambiguous identification of the analyzed signal by sight method. In the case of signals with positive SNR, the basing on the catalog data may be sufficient. The refinement of the software raster parameter values can be made based on the method of visual correction of image geometry distortions, i.e., by manually specifying the raster parameter values with simultaneous observation of the impact of their change on the quality of the reproduced image. However, in the case of sources of revealing emission signals, the parameters of which are unknown (especially in the case of highly noisy signals or those whose manufacturers do not provide such parameters, e.g., printers), it becomes necessary to have a tool that enables raster parameters to be determined in an automatic manner. The risk related to the loss of information may also apply to IoT devices equipped with graphic displays. Such devices can present data related to the operation of video intercoms, images from surveillance cameras, access manipulators, etc. [22; 23]. They can also be SmartOffice devices presenting the multitude of data related to the company's operations. Each display of such devices that process graphical data may become a source of undesirable emissions and constitute a risk of security [24; 25]. The aim of the article is to present the issues related to the influence of the accuracy of determining the raster parameters of an image on the quality of its reconstruction. Examples of rough estimation of image line length (Fourier transform) and its influence on the quality of the reconstructed image are presented. At the same time, the consequences of such a phenomenon on the possibility of using coherent summation to improve the signal-to-noise ratio are indicated. The emerging phenomenon forces the search for a more precise method of determining the length of the lines of the reconstructed image, which will affect the quality and thus the legibility of the data contained in the reconstructed image.