Browsing by Author "Wu, Han-Yan"

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A Multilayer Steganography Method with High Embedding Efficiency for Palette Images
(2020-07-01)
Wu, Han-Yan
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Chen, Ling-Hwei
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Ching, Yu-Tai
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資訊工程學系
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Department of Computer Science
Embedding efficiency is an important issue in steganography methods. Matrix embedding (1, n, h) steganography was proposed by Crandall to achieve high embedding efficiency for palette images. This paper proposes a steganography method based on multilayer matrix embedding for palette images. First, a parity assignment is provided to increase the image quality. Then, a multilayer matrix embedding (k, 1, n, h) is presented to achieve high embedding efficiency and capacity. Without modifying the color palette, hk secret bits can be embedded into n pixels by changing at most k pixels. Under the same capacity, the embedding efficiency of the proposed method is compared with that of pixel-based steganography methods. The comparison indicates that the proposed method has higher embedding efficiency than pixel-based steganography methods. The experimental results also suggest that the proposed method provides higher image quality than some existing methods under the same embedding efficiency and capacity.
A New Reference Pixel Prediction for Reversible Data Hiding with Reduced Location Map
(2014-03-31)
Chen, Jeanne
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Chen, Tung-Shou
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Hong, Wien
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Horng, Gwoboa
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Wu, Han-Yan
In this paper, a new reversible data hiding method based on a dual binary tree of embedding levels is proposed. Four neighborhood pixels in the upper, below, left and right of each pixel are used as reference pixels to estimate local complexity for deciding embeddable and non- embeddable pixels. The proposed method does not need to record pixels that might cause underflow, overflow or unsuitable for embedment. This can reduce the size of location map and release more space for payload. Experimental results show that the proposed method is more effective in increasing payload and improving image quality than some recently proposed methods.