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Automatyczne rozpoznawanie treści nielegalnych filmów typu CSAM za pomocą klasyfikatora częściowo splatającego kolejne klatki materiału wideo

Laskowska Barbara

Cybersecurity and Law

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2023

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Vol. 10 (2)

195--201

PL

Artykuł zawiera opis jednej z metod automatycznego wykrywania treści nielegalnych typu CSAM, którą przetestowano podczas badań przeprowadzanych w projekcie APAKT. Zaproponowane rozwiązanie wykorzystuje klasyfikator Temporal Shift Module (TSM), model sieci głębokiej do wydajnego rozpoznawania aktywności na plikach wideo. Zastosowano metodę z transferem wiedzy, żeby stosunkowo niedużą liczbą danych uczących nauczyć model skutecznego rozpoznawania treści pornograficznych i nielegalnych na filmach. Przeprowadzono testy skuteczności klasyfikacji na danych neutralnych legalnej i nielegalnej pornografii. W artykule wskazano również związane z tym tematem badawczym problemy, które wynikają z charakterystyki danych. Ponadto zwrócono uwagę na konieczność dalszych prac nad zapewnianiem bezpieczeństwa dzieci w cyberprzestrzeni.

EN

The paper describes one of the methods of automatic recognition of CSAM materials, which was tested during the research under the APAKT project. The proposed solution is based on Temporal Shift Module (TSM), a model of a deep neural network created for efficient human activities rocognition in video. We applied transfer learning method for training the model with a relatively small number of training data to succesfully rocognize films with pornografic and illegal content. We conducted some tests of classification of films from three categories: neutral films, legal pornography and illegal pornografic videos (CSAM). In this paper we present problems that are connected with this research topic that come from the characteristic of the data. We also show that further works are needed to keep children safe in cyberspace.

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Kinovea analysis of high-speed video recording to determine kinematics of double pendulum in the long time scale

Wojewoda Jerzy

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 6

art. no. e147918

EN

Measurement of position and velocity of rotating objects relies on installation of additional devices, which can significantly change their dynamic properties. Non-contact methods appear not to have the above-mentioned drawback. To determine the angular kinematics, a video measurement technique stands as a non-contact alternative. The rotational motion can be recorded with a high-speed camera and then analyzed with free and open-source tracking software which allows one to detect and digitize positions of chosen markers and then to calculate angular positions of selected elements. Differentiation process determines rotary speed values. Analysis of long-term dynamical behavior by recording data visualized as position maps which possess half of the information usually stored in the well-known Poincaré maps is proposed.

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Determining the shift of a bronchoscope catheter from the analysis of a video sequence of a bronchoscope video camera

Michalski D., Tabor Z., Zieliński B.

Biocybernetics and Biomedical Engineering

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2017

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Vol. 37, no. 4

630--636

EN

In this study we have proposed an algorithm for automated monitoring of the movements of a catheter used in peripheral bronchoscopy examination. We have shown that the shift of the catheter can be controlled in an automated way with quite a good accuracy by the means of analysis of video sequence recorded by a video camera of a bronchoscope. For a catheter moving between successive frames by no more than 1/3 of the distance between successive markers associated with a catheter the accuracy of a catheter shift measurement was equal to 1% and for a catheter moving between successive frames by no more than 1/2 of the distance between successive markers associated with a catheter the accuracy of a catheter shift measurement was equal to 5%. Visual inspection proved that the observed measurement errors were associated with faster movements of a catheter. Bronchoscope redesign option is proposed to improve catheter shift measurement accuracy. The results of this study demonstrate that application of image analysis techniques to data recorded during bronchoscopy examination can at least support the existing navigation methods for peripheral bronchoscopy with respect to the determination of the location of the catheter distal tip within the lumen of the pulmonary airways.