Browsing by Author "Chen, Shang-Kuan"

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An improved module-based substitution method for image hiding
(2008)
Chen, Shang-Kuan
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Lin, Ja-Chen
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Fu, Hung-Lin
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應用數學系
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資訊工程學系
The paper proposes an improved module-based substitution method for image hiding. The method has the following characteristics: (1) The extracted data are lossless. (2) Each k-bit datum is hidden in a pixel of the host image, and the gray-value distortion is not larger than 2(k-1) for most of the pixels. (3) If it is compared with reported lossless Least-Significant-Bits (LSB) or module-based methods, the proposed method is often with better stego-image quality, unless the hidden data are with very strong randomness. (4) The time complexity is also competitive.
AUTHENTICATION AND CROSS-RECOVERY OF MULTIPLE IMAGES
(2011-07-01)
Chen, Lee Shu-Teng
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Chen, Shang-Kuan
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Lin, Ja-Chen
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資訊工程學系
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Department of Computer Science
This work presents an authentication and cross-recovery scheme to protect a group of n JPEG images. Given n images, the images are scaled down and then encoded using JPEG to create n recovery data. Based on a pre-determined threshold t, 2 <= t < n, the n recovery data are shared to create n shadows. Next, n authentication data are generated to identify malicious attacks on the system. Additionally, the n shadows and the n authentication data are embedded in the n JPEG codes of the n original images to form n JPEG stego codes, which can be stored in a distributed storage system. Moreover, in the daily maintenance of the storage system, the authentication data concealed inside these n JPEG stego codes are used to verify which ones have been attacked. If some (up to n - t) of the n JPEG stego codes are corrupted, the corrupted JPEG images can be recovered approximately using any t survived JPEG stego codes. Experimental results demonstrate the effectiveness of the proposed method. Comparisons with other image recovery methods are also included.
Flip visual cryptography (FVC) with perfect security, conditionally-optimal contrast, and no expansion
(2010-11-01)
Lin, Sian-Jheng
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Chen, Shang-Kuan
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Lin, Ja-Chen
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資訊工程學系
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Department of Computer Science
This paper proposes a flip visual cryptography (FVC) scheme with perfect security, conditionally optimal contrast, and no expansion of size. The proposed FVC scheme encodes two secret images into two dual-purpose transparencies. Stacking the two transparencies can reveal one secret image. Flipping one of the two transparencies and then stacking with the other transparency can reveal the second secret image. The proposed scheme is proved to have conditionally optimal contrast: its contrast is optimal if the double-secrets non-expanded FVC scheme is required to have perfect security. The perfect security is also proved. (c) 2010 Elsevier Inc. All rights reserved.
Flip visual cryptography (FVC) with perfect security, conditionally-optimal contrast, and no expansion
(2010-11-01)
Lin, Sian-Jheng
;
Chen, Shang-Kuan
;
Lin, Ja-Chen
;
資訊工程學系
;
Department of Computer Science
This paper proposes a flip visual cryptography (FVC) scheme with perfect security, conditionally optimal contrast, and no expansion of size. The proposed FVC scheme encodes two secret images into two dual-purpose transparencies. Stacking the two transparencies can reveal one secret image. Flipping one of the two transparencies and then stacking with the other transparency can reveal the second secret image. The proposed scheme is proved to have conditionally optimal contrast: its contrast is optimal if the double-secrets non-expanded FVC scheme is required to have perfect security. The perfect security is also proved. (c) 2010 Elsevier Inc. All rights reserved.
Image hiding by LSB matching of higher payload
(2012)
Chen, Shang-Kuan
;
Lin, Ja-Chen
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交大名義發表
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National Chiao Tung University
LSB (Least significant bit) matching is a data hiding method that embeds message bits into a cover image by adding 0 or 1 or -1 to every cover pixel. Previous LSB matching methods were designed with 1 bpp (bits per pixel) as payload. By equalizing two values of distinct bases, the proposed LSB matching method can have a payload which is adjustable by the users, and the range is between 0 and 1.5849 bpp. Experimental results show that the quality of our stego-images is also competitive.