{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,7]],"date-time":"2026-03-07T17:55:03Z","timestamp":1772906103374,"version":"3.50.1"},"reference-count":23,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2024,9,28]],"date-time":"2024-09-28T00:00:00Z","timestamp":1727481600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National University of Science and Technology POLITEHNICA Bucharest\u2019s PUBART project"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Analysis of unintended compromising emissions from Video Display Units (VDUs) is an important topic in research communities. This paper examines the feasibility of recovering the information displayed on the monitor from reconstructed video frames. The study holds particular significance for our understanding of security vulnerabilities associated with the electromagnetic radiation of digital displays. Considering the amount of noise that reconstructed TEMPEST video frames have, the work in this paper focuses on two different approaches to de-noising images for efficient optical character recognition. First, an Adaptive Wiener Filter (AWF) with adaptive window size implemented in the spatial domain was tested, and then a Convolutional Neural Network (CNN) with an encoder\u2013decoder structure that follows both classical auto-encoder model architecture and U-Net architecture (auto-encoder with skip connections). These two techniques resulted in an improvement of more than two times on the Structural Similarity Index Metric (SSIM) for AWF and up to four times for the SSIM for the Deep Learning (DL) approach. In addition, to validate the results, the possibility of text recovery from processed noisy frames was studied using a state-of-the-art Tesseract Optical Character Recognition (OCR) engine. The present work aims to bring to attention the security importance of this topic and the non-negligible character of VDU information leakages.<\/jats:p>","DOI":"10.3390\/s24196292","type":"journal-article","created":{"date-parts":[[2024,9,30]],"date-time":"2024-09-30T07:19:37Z","timestamp":1727680777000},"page":"6292","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Comparative Approach to De-Noising TEMPEST Video Frames"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-8772-9601","authenticated-orcid":false,"given":"Alexandru M\u0103d\u0103lin","family":"Vizitiu","sequence":"first","affiliation":[{"name":"Faculty of Electronics, Telecommunications and Information Technology, National University of Sciences and Technologies Politehnica Bucharest, 060042 Bucharest, Romania"},{"name":"The Special Telecommunications Service, 060044 Bucharest, Romania"}]},{"given":"Marius Alexandru","family":"Sandu","sequence":"additional","affiliation":[{"name":"The Special Telecommunications Service, 060044 Bucharest, Romania"},{"name":"Center of Excellence in Robotics and Autonomous Systems\u2014CERAS, Military Technical Academy \u201cFerdinand I\u201d, 050141 Bucharest, Romania"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0028-5347","authenticated-orcid":false,"given":"Lidia","family":"Dobrescu","sequence":"additional","affiliation":[{"name":"Faculty of Electronics, Telecommunications and Information Technology, National University of Sciences and Technologies Politehnica Bucharest, 060042 Bucharest, Romania"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5236-8497","authenticated-orcid":false,"given":"Adrian","family":"Foc\u0219a","sequence":"additional","affiliation":[{"name":"Center of Excellence in Robotics and Autonomous Systems\u2014CERAS, Military Technical Academy \u201cFerdinand I\u201d, 050141 Bucharest, Romania"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4861-1620","authenticated-orcid":false,"given":"Cristian Constantin","family":"Molder","sequence":"additional","affiliation":[{"name":"Center of Excellence in Robotics and Autonomous Systems\u2014CERAS, Military Technical Academy \u201cFerdinand I\u201d, 050141 Bucharest, Romania"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1016\/0167-4048(85)90046-X","article-title":"Electromagnetic radiation from video display units: An eavesdropping risk?","volume":"4","author":"Eck","year":"1985","journal-title":"Comput. 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