## 1 Introduction  
The protection of information, understood as electromagnetic immunity to an electromagnetic infiltration process, is very important in the case of wireless communication. Very often, wireless communication is based on electronic devices equipped with graphic displays presenting the protected data. Their processing is protected by the use of cryptographic techniques. However, the display process is based on explicit, human-understood data. Then, they become a source of revealing emissions that can be used in the process of non-invasive acquisition [1, 2, 3]. The presentation in the form of an image of information processed in a device using the raster graphics technique for this purpose requires imaging (rasterization) parameters to be identified that enable the transformation of one-dimensional information signals (videosignals) into a two-dimensional matrix with dimensions corresponding to the parameters of the displayed image [4; 5; 6]. Based on the example of a typical monitor, it can be stated that its screen is made of points (pixels) capable of emitting radio waves, forming a matrix consisting of W rows and K columns, and the manner of this emission is determined by the video signal (a source of reveal emission). Based on the data contained in [7], the most important display parameters (image dimensions) of the information on the monitor can be given for selected operating modes (Table 1). In the case of generating the image in the device, these parameters are known, and the horizontal and vertical synchronization signals generated by the graphics card ensure correct imaging, even in the case of slight changes in their values. The situation is different in the case of reconstructing the information from the revealing signals. On the receiving side, without precise measurements that often require interference with the interior of the eavesdropped device, only the approximate values of the displaying parameters can be known. They are sufficient to display the information reproduced from signals with positive value of a signal to noise ratio (SNR). However, they are of little use in the case of very small SNR and the need to improve it using the coherent summation method. Then, the determined accuracy of the aforementioned parameters must be very high. Otherwise, the summation of the successive images obtained from the same revealing emission (RU) causes a deterioration of the image quality, not an improvement thereof. The phenomena of the formation of revealing emissions described in scientific publications and the possibility of using them in the process of electromagnetic infiltration are limited to studies of radiated and conducted emissions [8; 9; 10; 11; 12]. There are presented results of analyses of the impact of various solutions on the effectiveness of electromagnetic protection. The sources of the revealing emissions in the form of monitors, displays of multifunction devices or VoIP terminals and communication interfaces are analyzed [13]. Methods of data acquisition and attempts to present them graphically are presented [14; 15; 16]. There is no information about the impact of the accuracy of determining the image raster parameters (line length of the reconstructed image) on its quality and the possibility of efficiently applying the image summation method to improve the signal-to-noise ratio. Another widely analyzed area is the confirmation of the existence of revealing emissions, the analysis of the dependence of the processed signal structures on the efficiency of the emission source and an attempt to reconstruct information without indicating detailed