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Abstract:
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Good image quality and high hiding capacity are two basic requirements of information
hiding systems. Technically, it is very challenging to achieve these two factors
simultaneously. The purpose of obtaining either high hiding capacity or good image quality
are various from application to application. Inspired from the wet paper codes proposed by
Fridrich et al., we propose an information hiding scheme for grayscale images. The proposed
scheme first uses a secret key to randomly select a subset of pixels from a cover image as dry
pixels. Next, the toral automorphism is applied to the cover image to maximize the number of
dry pixel pairs. Then, each secret digit in the base-9 numeral system is embedded into one dry
pixel pair. The experimental results show that the proposed scheme can achieve good image
quality (i.e., PSNR > 46 dB) and flexible hiding capacity. In addition, unauthorized users
without knowing the secret key and the secret parameters used for the toral automorphism
can not extract the embedded message |
