• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권5호
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• pp.2723-2740
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• 2017

Steganographic schemes which are based on minimizing an additive distortion function defined the overall impacts after embedding as the sum of embedding costs for individual image element. However, mutual impacts during embedding are often ignored. In this paper, an adaptive JPEG steganographic method based on weight distribution for embedding costs is proposed. The method takes mutual impacts during embedding in consideration. Firstly, an analysis is made about the factors that affect embedding fluctuations among JPEG coefficients. Then the Distortion Update Strategy (DUS) of updating the distortion costs is proposed, enabling to dynamically update the embedding costs group by group. At last, a kind of adaptive JPEG steganographic algorithm is designed combining with the update strategy and well-known additive distortion function. The experimental result illustrates that the proposed algorithm gains a superior performance in the fight against the current state-of-the-art steganalyzers with high-dimensional features.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.551-555
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• 2008

In these days, compressed file is useful in internet environment and has many advantages. So a lot of data hiding algorithms works on JPEG compressed file. Of course they know basic rules of transformation and quantization and they utilize those rules to implement their programming. But most of them evaluate the affection of data hiding after data modification. We propose how to predict the affection of data modification in course of data hiding process. Through some kind of experiments, several valuable facts are revealed which used in data hiding in compressed domain such as JPEG. These facts will improve existing data hiding algorithms (F3, F4 and F5 which including Matrix Encoding)[1],[5],[6].

• 한국군사과학기술학회지
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• 제16권2호
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• pp.185-190
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• 2013

The previous steganographic methods by using the interpolation were difficult to estimate the distortion because the size of cover image is extended by interpolation algorithms. In this paper, to solve the problems of previous methods proposed the improved steganographic method based on the pixel replacement algorithms. In our method, we cannot extend a cover image, but also can estimate exactly the distortion of the stego-images. In the experimental results, the estimated distortion and embedding capacity of stego-image are shown on three pixel replacement methods.

• 방송공학회논문지
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• 제23권4호
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• pp.462-473
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• 2018

스테가노그래피란 숨기려는 정보를 미디어 데이터에 교묘하게 삽입하여 정보의 존재를 전혀 눈치 채지 못하도록 하는 데이터 은닉 기술의 하나이다. 데이터 암호화의 경우에는 정보 데이터에 직접 복호하기 어렵게 복잡한 부호화 기법을 이용하여 변형하는 것으로, 정보의 존재를 쉽게 인지할 수 있지만 복호를 어렵게 하는데 초점이 맞춰져 있다. 그러나 스테가노그래피는 다른 미디어에 정보를 자연스럽게 숨겨서 정보의 존재를 눈치 채지 못하게 함으로써, 더욱 강력하게 정보를 보호할 수 있다. 이 논문에서는 영상에 다른 영상 정보를 숨기는 영상 스테가노그래피의 개념을 소개하고, 스테가노그래피 부호화 여부를 판별하는 기법을 제안한다. 주로 영상 픽셀의 LSB (Least Significant Bit)를 조작하는 공간영역의 기법과, JPEG 압축시 DCT 계수를 조작하는 주파수 영역의 영상 스테가노그래피를 소개하고, 이들의 스테가노그래피 부호화 여부와 복호결과를 판별하는 새로운 방법을 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3298-3321
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• 2021

A lot of data hiding schemes have been proposed to embed secret data in the plain cover images or compressed images of various formats, including JPEG, AMBTC, VQ, etc. In this paper, we propose a production process of mosaic images based on three regular images of coffee beans. A primary image is first mimicked by the process to produce a mosaic cover image. A two-layer steganography is applied to hide secret data in the mosaic image. Based on the low visual quality of the mosaic cover image, its PSNR value can be improved about 1.5 dB after embedding 3 bpp. This is achieved by leveraging the newly proposed polarized search mask and the concepts of strong embedding and weak embedding. Applying steganography to the mosaic cover images is a completely new idea and it is promising.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권8호
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• pp.3911-3925
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• 2018

This paper proposes a novel steganography method to hide secret data during the generation of tangle patterns. Different from the traditional steganography based on modifying natural images, we propose to construct stego images according to the secret messages. We first create a model to group a selected image contour, and define some basic operations to generate various pattern cells. During data hiding, we create a cell library to establish the relationships between cells and secret data. By painting the cell inside the image contour, we create a dense tangle pattern to carry secret data. With the proposed method, a recipient can extract the secret data correctly. Experimental results show that the proposed method has a flexible embedding capacity. The constructed stego tangle image has good visual effects, and is secure against adversaries. Meanwhile, the stego tangle pattern is also robust to JPEG compression.

• 전자공학회논문지CI
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• 제46권1호
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• pp.56-63
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• 2009

최근에는 인터넷 환경에서 여러 형태의 압축된 파일이 이용되고 있으며 통신량의 감소, 통신시간의 절약 등 많은 장점을 가지고 있다. JPEG 압축의 경우, 양자화는 영상의 압축을 달성하기 위해 중요한 과정중의 하나이다. 일반적인 신호처리에서 양자화는 연속적인 아날로그 신호를 이산적인 디지털 신호로 변환하는 것이 주요 목적이다. 하지만 JPEG에서의 양자화는 시간영역의 픽셀 값 또는 주파수 영역의 계수 값의 크기를 줄이는 역할을 한다. 많은 압축 기법 그리고 압축 기법에서 동작하는 영상처리기법들이 개발되어 지고 있다. 정보 은닉에서도 JPEG과 같은 압축파일에서 동작하는 알고리즘이 개발되어 지고 있다. 우리는 이 논문에서 정보은닉 처리과정에서 생겨나는 데이터 변경의 영향을 예측하기 위한 방법을 제안하였다. JPEG과 같은 압축 환경에서 정보 은닉 시 적용 가능한 몇 가지 중요한 사실을 여러 경우의 실험을 통하여 얻어냈다. 이러한 사실들은 현재 존재하는(Matrix Encoding, Modified Matrix Encoding 등을 포함한 F3, F4 and F5 알고리즘 등) 정보은닉 프로그램의 성능향상, 알고리즘 처리시간의 감소와 같은 긍정적인 효과를 거둘 수 있다.

• ETRI Journal
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• 제35권3호
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• pp.512-522
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• 2013

In this paper, the radius weight mean (RWM) and the feature-embedding technique are used to present a novel watermarking scheme for color images. Simulations validate that the stego-images generated by the proposed scheme are robust against most common image-processing operations, such as compression, color quantization, bit truncation, noise addition, cropping, blurring, mosaicking, zigzagging, inversion, (edge) sharpening, and so on. The proposed method possesses outstanding performance in resisting high compression ratio attacks: JPEG2000 and JPEG. Further, to provide extra hiding storage, a steganographic method using the RWM with the least significant bit substitution technique is suggested. Experiment results indicate that the resulting perceived quality is desirable, whereas the peak signal-to-noise ratio is high. The payload generated using the proposed method is also superior to that generated by existing approaches.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2000년도 추계학술발표논문집 (상)
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• pp.153-156
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• 2000

인터넷을 비롯한 통신기술의 비약적인 발전과 보급, Mpeg, Jpeg 등의 멀티미디어 데이터 압축기술의 발전으로 인하여 문서, 사진, 동영상, 오디오 데이터 등의 다양한 매체들이 디지털화되어 고속으로 전송이 가능하게 되었다. 이러한 멀티미디어 컨텐츠(Multimedia Contents)에 대해 누구나 쉽게 저장과 접근, 이용 가능하게 됨으로써 저작물에 대한 소유권 문제가 큰 이슈로 부각되었다. 본 논문에서는 이러한 멀티미디어 데이터의 저작권을 보호하기 위한 방법들을 살펴보고 각 기법의 특성을 고찰한다. 또한 각 기법들간의 관계 및 체계를 분류하고 저작권 보호에 효율적인 워터마킹(Watermarking)기법과 스테가노그라피(Steganography) 및 핑거프린팅(Fingerprinting)기법을 비교 분석한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권4호
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• pp.1248-1266
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• 2012

This paper presents a multilevel reversible data hiding method based on histogram shifting which can recover the original image losslessly after the hidden data has been extracted from the stego-image. The method of prediction is adopted in our proposed scheme and prediction errors are produced to explore the similarity of neighboring pixels. In this article, we propose two different predictors to generate the prediction errors, where the prediction is carried out using the center prediction method and the JPEG-LS median edge predictor (MED) to exploit the correlation among the neighboring pixels. Instead of the original image, these prediction errors are used to hide the secret information. Moreover, we also present an improved method to search for peak and zero pairs and also talk about the analogy of the same to improve the histogram shifting method for huge embedding capacity and high peak signal-to-noise ratio (PSNR). In the one-level hiding, our method keeps image qualities larger than 53 dB and the ratio of embedding capacity has 0.43 bpp (bit per pixel). Besides, the concept with multiple layer embedding procedure is applied for obtaining high capacity, and the performance is demonstrated in the experimental results. From our experimental results and analytical reasoning, it shows that the proposed scheme has higher PSNR and high data embedding capacity than that of other reversible data hiding methods presented in the literature.