• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.588-591
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• 2009

This paper proposes a reversible information hiding method for binary images. A half of pixels in noisy blocks on cover images is candidate for embeddable pixels. Among the candidate pixels, we select compressive pixels by bit patterns of its neighborhood to compress the pixels effectively. Thus, embeddable pixels in the proposed method are compressive pixels in noisy blocks. We provide experimental results using several binary images binarized by the different methods.

• Journal of Electrical Engineering and Technology
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• 제11권4호
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• pp.974-986
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• 2016

Reversible image watermarking, a type of digital data hiding, is capable of recovering the original image and extracting the hidden message with precision. A number of reversible algorithms have been proposed to achieve a high embedding capacity and a low distortion. While numerous algorithms for the achievement of a favorable performance regarding a small embedding capacity exist, the main goal of this paper is the achievement of a more favorable performance regarding a larger embedding capacity and a lower distortion. This paper therefore proposes a reversible data hiding algorithm for which a novel piecewise 2D auto-regression (P2AR) predictor that is based on a rhombus-embedding scheme is used. In addition, a minimum description length (MDL) approach is applied to remove the outlier pixels from a training set so that the effect of a multiple linear regression can be maximized. The experiment results demonstrate that the performance of the proposed method is superior to those of previous methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4603-4624
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• 2016

In this paper, a new reversible watermarking algorithm with adaptive embedding threshold matrix is proposed. Firstly, to avoid the overflow and underflow, two flexible thresholds, TL and TR, are applied to preprocess the image histogram with least histogram shift cost. Secondly, for achieving an optimal or near optimal tradeoff between the embedding capacity and imperceptibility, the embedding threshold matrix, composed of the embedding thresholds of all blocks, is determined adaptively by the combination between the composite chaos and the average energy of Integer Wavelet Transform (IWT) block. As a non-liner system with good randomness, the composite chaos is suitable to search the optimal embedding thresholds. Meanwhile, the average energy of IWT block is calculated to adjust the block embedding capacity, and more data are embedded into those IWT blocks with larger average energy. The experimental results demonstrate that compared with the state-of-the-art reversible watermarking schemes, the proposed scheme has better performance for the tradeoff between the embedding capacity and imperceptibility.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권7호
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• pp.2572-2589
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• 2014

Reversible data hiding is a technique for recovering original images without any distortion after secret data are extracted from the image. The technique continues to attract attention from many researchers. In this paper, we introduce a new reversible data hiding scheme based on the adjacent index differences of vector quantization (VQ) indices. The proposed scheme exploits the differences between two adjacent indices to embed secret data. Experimental results show that our scheme can achieve a lower compression rate than an earlier scheme by Yang and Lin. Our scheme's average compression rate, 0.44 bpp, outperforms that of Yang and Lin's scheme, which averages 0.53 bpp. Moreover, the embedding capacity of our scheme can rise to 1.45 bpi, which also is superior to that of Chang et al.'s scheme [35] (1.00 bpi)Yang and Lin's scheme [27] (0.91 bpi) as well as Chang et al.'s scheme [26] (0.74 bpi).

• 한국정보전자통신기술학회논문지
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• 제9권6호
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• pp.573-577
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• 2016

본 논문에서는 영상의 지역성과 인접 픽셀 차분시퀀스를 이용하는 가역 데이터 임베딩 기법을 제안하였다. 자연영상에는 일반적으로 지역성이 존재한다. 영상의 지역성을 이용하여 인접한 픽셀 값을 예측하는 기법을 기존의 기법인 APD(Adjacent Pixel Difference) 기법에 적용하여 임베딩 가능한 데이터 량을 증가 시키고 다양한 레벨로 데이터 임베딩을 가능하게 하는 가역 데이터 임베딩 기법을 제안하였다. 실험결과를 통하여 제안된 기법의 우수성을 확인하였다.

• 한국컴퓨터정보학회논문지
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• 제21권8호
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• pp.1-12
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• 2016

In this paper, we propose a very efficient reversible data hiding algorithm using spatial locality and the surface characteristics of image. Spacial locality and a variety of surface characteristics are present in natural images. So, it is possible to precisely predict the pixel value using the locality and surface characteristics of image. Therefore, the frequency is increased significantly at the peak point of the difference histogram using the precisely predicted pixel values. Thus, it is possible to increase the amount of data to be embedded in image using the spatial locality and surface characteristics of image. By using the proposed reversible data hiding algorithm, visually high quality stego-image can be generated, the embedded data and the original cover image can be extracted without distortion from the stego-image, and the embedding data are much greater than that of the previous algorithm. The experimental results show the superiority of the proposed algorithm.

• 한국컴퓨터정보학회논문지
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• 제21권2호
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• pp.33-42
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• 2016

In this paper, an advanced reversible data hiding algorithm which takes the advantage of the spatial locality in image was proposed. Natural image has a spatial locality. The pixel value of a natural image is similar to the values of neighboring pixels. So, using the neighboring pixel values, it is possible to precisely predict the pixel value. Frequency increases significantly at the peak point of the difference histogram using the predicted values. Therefore, it is possible to increase the amount of data to be embedded. By using the proposed algorithm, visually high quality stego-image can be generated, the original cover image and the embedded data can be extracted from the stego-image without distortion. The embedding data into the cover image of the proposed algorithm is much lager than that of the previous algorithm. The performance of the proposed algorithm was verified by experiment. The proposed algorithm is very useful for the reversible data hiding.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.458-461
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• 2000

Variable length codes are often used in entropy coding, but are very vulnerable in noisy environments. Reversible variable length codes, however, muse possible to decode instantaneously in both forward and backward directions, so that more usable data can be retrieved when bit errors occur via transmission. Furthermore, partial decodability is desirable to introduce in the reversible variable length code because ROI (Region Of Interest) decoding function is sometimes required in recent image information systems such as the medical imaging, the digital museum and so on. In this paper, we propose a partially decodable and reversible variable length code by modifying Golomb-Rice code.

• ETRI Journal
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• 제33권4호
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• pp.580-588
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• 2011

This paper proposes reversible data hiding using minimum/maximum preserved overflow/underflow avoidance (MMPOUA). The proposed MMPOUA algorithm consists of three main steps. These steps include the minimum (or maximum) pixel fixing, pixel squeezing, and pixel isolation. The aims of pixel fixing are to keep the minimum (or maximum) pixel of a host block unchanged and prevent the occurrence of overflow/underflow. Both the pixel squeezing and pixel isolation supply hiding storage while keeping the amount of distortion low. The proposed method can avoid (or significantly reduce) the overhead bits used to overcome overflow/underflow issues. At an embedding rate of 0.15 bpp, the proposed algorithm can achieve a PSNR value of 48.52 dB, which outperforms several existing reversible data hiding schemes. Furthermore, the algorithm performed well in a variety of images, including those in which other algorithms had difficulty obtaining good hiding storage with high perceived quality.

• Journal of Information Processing Systems
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• 제11권3호
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• pp.406-420
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• 2015

We present a secure and robust image watermarking scheme that uses combined reversible DWT-DCT-SVD transformations to increase integrity, authentication, and confidentiality. The proposed scheme uses two different kinds of watermarking images: a reversible watermark, $W_1$, which is used for verification (ensuring integrity and authentication aspects); and a second one, $W_2$, which is defined by a logo image that provides confidentiality. Our proposed scheme is shown to be robust, while its performances are evaluated with respect to the peak signal-to-noise ratio (PSNR), signal-to-noise ratio (SNR), normalized cross-correlation (NCC), and running time. The robustness of the scheme is also evaluated against different attacks, including a compression attack and Salt & Pepper attack.