Robust Steganography by Modifying Sign of DCT Coefficients

In this paper, we propose a frequency domain data hiding method for the JPEG compressed images. The proposed method embeds data in the DCT coefficients of the selected 8 × 8 blocks. According to the theories of Human Visual Systems (HVS), human vision is less sensitive to perturbation of pixel values in the uneven areas of the image. In this paper we propose a Singular Value Decomposition based image roughness measure (SVD-IRM) using which we select the coarse 8 × 8 blocks as data embedding destinations. Moreover, to make the embedded data more robust against re-compression attack and error due to transmission over noisy channels, we employ Turbo error correcting codes. The actual data embedding is done using a proposed variant of matrix encoding that is capable of embedding three bits by modifying only one bit in block of seven carrier features. We have carried out experiments to validate the performance and it is found that the proposed method achieves better payload capacity and visual quality and is more robust than some of the recent state-of-the-art methods proposed in the literature.

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An Improved Face Recognition Algorithm Using Quantized DCT Coefficients

2011 Seventh International Conference on Signal Image Technology & Internet-Based Systems ◽

10.1109/sitis.2011.62 ◽

2011 ◽

Author(s):

Qiu Chen ◽

Koji Kotani ◽

Feifei Lee ◽

Tadahiro Ohmi

Keyword(s):

Face Recognition ◽

Recognition Algorithm ◽

Dct Coefficients

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A DCT-Domain System for Digital Watermarking

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.321-324.2609 ◽

2013 ◽

Vol 321-324 ◽

pp. 2609-2612

Author(s):

Yan Liang ◽

Gao Yan ◽

Chun Xia Qi

Keyword(s):

Signal Processing ◽

Digital Watermarking ◽

Copyright Protection ◽

Random Sequence ◽

Multimedia Data ◽

Dct Domain ◽

Digital Document ◽

Dct Coefficients ◽

Processing Techniques ◽

Signal Processing Techniques

Digital watermarking has been proposed as a solution to the problem of copyright protection of multimedia data in a networked environment. It makes possible to tightly associated to a digital document a code allowing the identification of the data creator, owner, authorized consumer, and so on. In this paper a new DCT-domain system for digital watermarking algorithm for digital images is presented: the method, which operates in the frequency domain, embeds a pseudo-random sequence of scrambled image in a selected set of DCT coefficients. After embedding, the watermark is adapted to the image by exploiting the masking characteristics of the human visual system, thus ensuring the watermark invisibility. By exploiting the statistical properties of the embedded sequence, the mark can be reliably extracted without resorting to the original uncorrupted image. Experimental results demonstrate that the watermark is robust to several signal processing techniques, including JPEG compression, cut, fuzzy, addition of noise, and sharpen.

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