King JUNG's History

Data hiding in two-colour images is difficult since 1 pixel requires only 1 bit representation and it is easy to detect for pixel distortion. In this paper, we describe a new data hiding method for two-colour images by two-stage referencing. The cover image is partitioned into n x n non-overlapping sub-blocks, and we calculate difference values by two stages for all pixels to find the suitable replacement pixel. The two-stage referencing is to obtain difference values that are different with the current pixel value for neighbouring pixels with n x n and
(n+2) x (n+2). These two difference values are used to embed a secret bit on the sub-block. The experimental results show that the proposed method achieves a good visual quality for the stego-image.

The Imaging Science Journal, vol. 61 (2013) 475-483 (SCI)
ISSN : 1368-2199 (http://www.maney.co.uk)

Steganography-2.pdf

In this paper, we propose a high capacity steganographic method using modulus function of pixel-value differencing (PVD) and least significant bit (LSB) replacement methods. The main idea of the proposed method is that secret data can be embedded on the smooth area by LSB substitution and on the edge area by PVD with less distortion to the human visual system and improvement of the embedding capacity. The experimental results show that the proposed method sustains a higher capacity and still a good quality compared with LSB and PVD methods.

The Imaging Science Journal, Vol. 58, 2010, pp.213~221 (SCI)
ISSN : 1368-2199 (http://www.maney.co.uk)

A novel data hiding method based on the least significant bit (LSB) substitution and the multi-pixel differencing (MPD) method is presented on the proposed method to improve the capacity of hidden secret data and to provide an imperceptible visual quality. First, a sum of different values for a four-pixel sub-block is calculated. The low value of the sum can be located on a smooth block and the high value is located on an edged block. The secret data are hidden into the cover image by the LSB method in the smooth block, while the MPD method is concealed in the edged block. The experimental results show that the proposed method has a higher capacity and maintains good visual quality.

ICHIT, International Conference on Convergence and Hybrid Information Technology, 2008, pp.355-358

Wu and Tsai's pixel-value differencing method and Chang and Tseng's side-match method are based on the theory that the number of bits which can be embedded is determined by the degree of the pixel's smoothness, or its proximity to the edge of the image. If pixels are located in the edge area, they may tolerate larger changes than those in smooth areas. However, both methods are subject to the fall off the boundary problem(FOBP). This study proposes a new scheme that can solve the FOBP. The experimental results demonstrate that the proposed method resolves the problem, and achieves a higher image quality index value than other methods.

한국군사과학기술학회지, 제11권 제3호(2008년6월) pp. 115-122

This paper proposes a new data hiding method for binary images using the weighting value of pixel-value differencing. The binary cover image is partitioned into non-overlapping sub-blocks and find the most suitable position to embed a secret bit for each sub-block. The proposed method calculates the weighted value for a sub-block to pivot a pixel to be changed. This improves the image quality of the stego-image. The experimental results show that the proposed method achieves a good visual quality and high capacity.

한국군사과학기술학회지, 제11권 제4호(2008년8월) pp. 53-60

The EMD method proposed by Zhang and Wang fully exploited modification directions. Modifications in different directions were used to represent different secret data, where only one secret digit is embedded for each two pixels. To improve an embedding capacity, Chang et al. proposed two-stage EMD method, Lee et al. restricted to 8-ary embedding for the EMD method, and also Lee et al. segmented the pair of cover data into two parts to embed higher secret data. But still have a room for hiding more secret data. This paper proposes an improved method of the EMD method to hide more secret data while maintaining a high PSNR value. The proposed method can embed secret bit on every pixel of cover data.

International Journal of Signal Processing, Image Processing and Pattern, Vol. 2, No.1, March, 2009. pp. 79-88

Secret data hiding in binary images is more difficult than other formats since binary images require only one bit representation to indicate black and white. This study proposes a new method for data hiding in binary images using optimized bit position to replace a secret bit. This method manipulates blocks, which are sub-divided. The parity bit for a specified block decides whether to change or not, to embed a secret bit. By finding the best position to insert a secret bit for each divided block, the image quality of the resulting stego-image can be improved, while maintaining low computational complexity.

Journal of Software Engineering and Applications, April 2009 pp. 20-24

We have proposed two data hiding methods based on the RLM encoding. All of the proposed method used the length of the location, which compared the run length of the cover data and that of the secret data. The RLM method used the run length table constructed from the cover and secret data, whereas the RRLM method used the difference value of the cover and secret data before making the run length encoding table. Our experimental results have shown that the proposed methods provided a better way to hide secret data compared with four other methods.

International Journal of Intelligent Information and Database Systems, Vol. 3, No. 3, 2009, pp.311–325 (SCOPUS)

This paper proposes a new interpolation and a data hiding method. The proposed scaling-up neighbor mean interpolation method has a low-time complexity and high-calculation speed. The proposed data hiding method is based on interpolation. Comparison on data hiding methods is divided into reversible or not. Our experimental results show the proposed method can embed a large amount of secret data while keeping a very high visual quality, the PSNR is guaranteed to be higher than 35 dB compared with other reversible data hiding methods. And also capacity is larger than any other reversible data hiding methods.

Computer Standards & Interfaces, volume 31, Issue 2 (Feb 2009) pp. 465-470 (SCIE)