TCC - Engenharia Eletrônica (UACSA)
URI permanente para esta coleçãohttps://arandu.ufrpe.br/handle/123456789/2917
Navegar
2 resultados
Resultados da Pesquisa
Item Um estudo sobre ocultação de dados para imagens digitais(2023-04-26) Mendonça, Thatyta de Sousa Silva; Ferreira, Felipe Alberto Barbosa Simão; http://lattes.cnpq.br/9939255113143786; http://lattes.cnpq.br/2783767585088280Digital security is a growing field of study in various areas of science, which includes stega- nography - the art of writing in a hidden manner - as one of the new research areas. This undergraduate thesis presents the implementation of a Least Significant Bit (LSB) steganographic technique to embed text messages in image files. The study is based on literature research on data hiding techniques in digital images and the importance of using watermarking as a measure of protection against piracy and image forgery. The paper presents the theoretical concepts involved in the LSB technique, as well as the methods and tools used for the insertion of the digital watermark. The results obtained from tests conducted prove the effectiveness of the LSB technique in securely and efficiently embedding digital watermarks in digital images.Item Projeto de marca d’água digital do tipo frágil para nuvens de pontos 3D baseado em processamento de sinais sobre grafos(2023-09-20) Silva, João Victor da; Ferreira, Felipe Alberto Barbosa Simão; http://lattes.cnpq.br/9939255113143786; https://lattes.cnpq.br/1535688689643312Applications based on 3D models have been constantly gaining prominence due to their higher fidelity and real-world applicability. To achieve this, it is necessary to seek more suitable alternatives for data acquisition, encoding, representation, visualization, and protection. Given the importance of signal processing in preserving the integrity and authenticity of point clouds, there arises a need for advanced approaches that ensure the security and protection of this data. In this context, research and development of a digital watermarking project based on graph signal processing have emerged. This approach aims not only to enhance the protection of this data but also to identify any unwanted and malicious modifications that may occur. To this end, this work presents the creation of a fragile watermarking method for 3D point clouds with the intention of evaluating both its robustness against attacks and its effectiveness. Furthermore, we seek to implement a practical solution that allows the application of this digital watermark directly to 3D point clouds, with the purpose of preserving their integrity and authenticity, protecting them against possible unwanted or malicious modifications. In this way, a literature review is conducted, followed by simulations using databases of real models, using graph signal processing tools (GSP), applying the graph Fourier transform (GFT) technique. The databases used for the simulations were extracted from various research sources, including Oxford RobotCar, KITTI, NuScenes, among others. The metrics responsible for evaluating the performance of the proposed technique are Peak Signal-to-Noise Ratio (PSNR), Root Mean Squared Error (RMSE), and Bit Error Ratio (BER). As a result, it is observed that the proposed digital watermarking method shows satisfactory results in terms of robustness against attacks and preservation of the quality of 3D data. The experiments have demonstrated the feasibility and efficiency of implementing the digital watermark in 3D point clouds. Therefore, it is concluded that the use of a digital watermark based on graph signal processing is a promising solution to ensure the security and authenticity of 3D data in various applications.