Temat: watermarking - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Wytwarzanie znaku wodnego w czasie rzeczywistym
Watermark generation in real time
Autorzy:: Bogdan, B.
Łopatka, J.
Powiązania:: https://bibliotekanauki.pl/articles/208358.pdf
Data publikacji:: 2006
Wydawca:: Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:: telekomunikacja
znak wodny
DSP
MPEG
telecommunication
watermarking
Opis:: Artykuł przedstawia jedną z metod generacji oraz opis funkcjonalny generatora znaku wodnego, działającego w czasie rzeczywistym. Generator ten jest jednym z elementów systemu znakowania sygnału akustycznego dla potrzeb transmisji danych w kanałach akustycznych. W artykule przedstawiono budowę generatora, sposób wytwarzania znaku wodnego oraz dodawania go do sygnału akustycznego z wykorzystaniem techniki DSP.
The paper presents a method of watermark signal generation and functional description of a real time watermark signal generator. This generator was designed for transmission of a hidden signature over transmission channels. Generator structure, inner structure of a watermark signal, and the used model of psycho-acoustic mask are described.
Źródło:: Biuletyn Wojskowej Akademii Technicznej; 2006, 55, sp.; 83-91
1234-5865
Pojawia się w:: Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Efficient and robust medical image watermarking based on optimal subband tree structuring and discrete fractional fourier transform
Autorzy:: Chacko, Anusha
Chacko, Shanty
Powiązania:: https://bibliotekanauki.pl/articles/38705179.pdf
Data publikacji:: 2023
Wydawca:: Instytut Podstawowych Problemów Techniki PAN
Tematy:: medical image
watermarking
FFT
decomposition
security
obraz medyczny
znak wodny
rozkład
bezpieczeństwo
Opis:: In order to solve the security problems associated with medical information and improve the robustness of watermarking algorithms for medical images, a unique approach to watermarking based on block operations is presented. This study considers the medical images as the cover image, with the watermark logo considered secret information that needs to be protected over the wireless transmission in telemedicine. In the embedding phase, input with the discrete fractional Fourier transform is first applied to the input, and then level 2 wavelet decomposition is carried out to determine the optimal sub-band tree. For each tree node on level 2, the approximated and detailed coefficient is determined through the feature analysis perspective. The novelty of the adopted methodology is its simplified transformation and embedding process. Upon receiving a complex matrix, it separates the real part from imaginary part where block transformation is carried out for embedding the watermark pixels. In the extraction phase, just a reverse operation is performed. The watermarking evaluation is performed by simulating various image processing attacks on watermarked medical images. The simulation outcome demonstrates the effectiveness of that proposed watermarking scheme against various attacks. The proposed watermarking technique is robust under various attacks based on image statistics such as PSNR, BER, and the correlation coefficient.
Źródło:: Computer Assisted Methods in Engineering and Science; 2023, 30, 4; 557-581
2299-3649
Pojawia się w:: Computer Assisted Methods in Engineering and Science
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Verification of iris image authenticity using fragile watermarking
Autorzy:: Czajka, A.
Kasprzak, W.
Wilkowski, A.
Powiązania:: https://bibliotekanauki.pl/articles/200546.pdf
Data publikacji:: 2016
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: biometric data authentication
iris recognition
steganography
watermarking
dane biometryczne
rozpoznawanie tęczówki
steganografia
znak wodny
Opis:: This paper proposes and evaluates a watermarking-based approach to certify the authenticity of iris images when they are captured by a genuine equipment. In the proposed method, the iris images are secretly signed before being used in biometric processes, and the resulting signature is embedded into the JPEG carrier image in the DCT domain in a data-dependent way. Any alteration of the original (certified) image makes the signature no longer corresponding to this image and this change can be quickly identified at the receiver site. Hence, it is called fragile watermarking to differentiate this method from regular watermarking that should present some robustness against image alterations. There is no need to attach any auxiliary signature data, hence the existing, already standardized transmission channels and storage protocols may be used. The embedding procedure requires to remove some part of the original information. But, by using the BATH dataset comprising 32 000 iris images collected for 1 600 distinct eyes, we verify that the proposed alterations have no impact on iris recognition reliability, although statistically significant, small differences in genuine score distributions are observed when the watermark is embedded to both the enrollment and verification iris images. This is a unique evaluation of how the watermark embedding of digital signatures into the ISO CROPPED iris images (during the enrollment, verification or both) influences the reliability of a well-established, commercial iris recognition methodology. Without loss in generality, this approach is targeted to biometric-enabled ID documents that deploy iris data to authenticate the holder of the document.
Źródło:: Bulletin of the Polish Academy of Sciences. Technical Sciences; 2016, 64, 4; 807-819
0239-7528
Pojawia się w:: Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:: Biblioteka Nauki

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