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Biomedical Image Watermarking in Wavelet Domain for Data Integrity Using Bit Majority Algorithm and Multiple Copies of Hidden Information
American Journal of Biomedical Engineering , 2012, DOI: 10.5923/j.ajbe.20120202.06
Abstract: The current paper presents a novel and unique scheme for biomedical image watermarking in wavelet domain by hiding multiple copies of the same data in the cover image using bit replacement in the horizontal (HL) and vertical (LH) resolution approximation image components. The proposed scheme uses an approach for recovering the hidden information from the damaged copies due to unauthorized alteration of the data by applying an algorithm to find the closest twin of the embedded information by bit majority algorithm. Experimental results of the proposed watermarking technique show much enhancement in the visual and statistical invisibility of hidden information after data recovery that supports the improvement in performance.
Securing Biometric Images using Reversible Watermarking  [PDF]
Sabu M. Thampi,Ann Jisma Jacob
Computer Science , 2011,
Abstract: Biometric security is a fast growing area. Protecting biometric data is very important since it can be misused by attackers. In order to increase security of biometric data there are different methods in which watermarking is widely accepted. A more acceptable, new important development in this area is reversible watermarking in which the original image can be completely restored and the watermark can be retrieved. But reversible watermarking in biometrics is an understudied area. Reversible watermarking maintains high quality of biometric data. This paper proposes Rotational Replacement of LSB as a reversible watermarking scheme for biometric images. PSNR is the regular method used for quality measurement of biometric data. In this paper we also show that SSIM Index is a better alternate for effective quality assessment for reversible watermarked biometric data by comparing with the well known reversible watermarking scheme using Difference Expansion.
Securing Biometric Images using Reversible Watermarking
Sabu M. Thampi & Ann Jisma Jacob
International Journal of Image Processing , 2011,
Abstract: Biometric security is a fast growing area. Protecting biometric data is very important since it canbe misused by attackers. In order to increase security of biometric data there are differentmethods in which watermarking is widely accepted. A more acceptable, new importantdevelopment in this area is reversible watermarking in which the original image can becompletely restored and the watermark can be retrieved. But reversible watermarking inbiometrics is an understudied area. Reversible watermarking maintains high quality of biometricdata. This paper proposes Rotational Replacement of LSB as a reversible watermarkingscheme for biometric images. PSNR is the regular method used for quality measurement ofbiometric data. In this paper we also show that SSIM Index is a better alternate for effectivequality assessment for reversible watermarked biometric data by comparing with the well knownreversible watermarking scheme using Difference Expansion.
Reversible Watermarking Using Statistical Information  [cached]
Ahmad Mahmoudi Aznaveh,Farah Torkamani-Azar,Azadeh Mansouri,Fatih Kurugollu
EURASIP Journal on Advances in Signal Processing , 2010, DOI: 10.1155/2010/738972
Abstract: In most reversible watermarking methods, a compressed location map is exploited in order to ensure reversibility. Besides, in some methods, a header containing critical information is appended to the payload for the extraction and recovery process. Such schemes have a highly fragile nature; that is, changing a single bit in watermarked data may prohibit recovery of the original host as well as the embedded watermark. In this paper, we propose a new scheme in which utilizing a compressed location map is completely removed. In addition, the amount of auxiliary data is decreased by employing the adjacent pixels information. Therefore, in addition to quality improvement, independent authentication of different regions of a watermarked image is possible.
Reversible Watermarking Using Statistical Information  [cached]
Mahmoudi Aznaveh Ahmad,Torkamani-Azar Farah,Mansouri Azadeh,Kurugollu Fatih
EURASIP Journal on Advances in Signal Processing , 2010,
Abstract: In most reversible watermarking methods, a compressed location map is exploited in order to ensure reversibility. Besides, in some methods, a header containing critical information is appended to the payload for the extraction and recovery process. Such schemes have a highly fragile nature; that is, changing a single bit in watermarked data may prohibit recovery of the original host as well as the embedded watermark. In this paper, we propose a new scheme in which utilizing a compressed location map is completely removed. In addition, the amount of auxiliary data is decreased by employing the adjacent pixels information. Therefore, in addition to quality improvement, independent authentication of different regions of a watermarked image is possible.
Very fast watermarking by reversible contrast mapping  [PDF]
Dinu Coltuc,Jean-Marc Chassery
Mathematics , 2007, DOI: 10.1109/LSP.2006.884895
Abstract: Reversible contrast mapping (RCM) is a simple integer transform that applies to pairs of pixels. For some pairs of pixels, RCM is invertible, even if the least significant bits (LSBs) of the transformed pixels are lost. The data space occupied by the LSBs is suitable for data hiding. The embedded information bit-rates of the proposed spatial domain reversible watermarking scheme are close to the highest bit-rates reported so far. The scheme does not need additional data compression, and, in terms of mathematical complexity, it appears to be the lowest complexity one proposed up to now. A very fast lookup table implementation is proposed. Robustness against cropping can be ensured as well.
Reversible Watermarking Algorithm with Distortion Compensation  [cached]
Sachnev Vasiliy,Kim HyoungJoong,Suresh Sundaram,Shi YunQing
EURASIP Journal on Advances in Signal Processing , 2010,
Abstract: A novel reversible watermarking algorithm with two-stage data hiding strategy is presented in this paper. The core idea is two-stage data hiding (i.e., hiding data twice in a pixel of a cell), where the distortion after the first stage of embedding can be rarely removed, mostly reduced, or hardly increased after the second stage. Note that even the increased distortion is smaller compared to that of other methods under the same conditions. For this purpose, we compute lower and upper bounds from ordered neighboring pixels. In the first stage, the difference value between a pixel and its corresponding lower bound is used to hide one bit. The distortion can be removed, reduced, or increased by hiding another bit of data by using a difference value between the upper bound and the modified pixel. For the purpose of controlling capacity and reducing distortion, we determine appropriate threshold values. Finally, we present an algorithm to handle overflow/underflow problems designed specifically for two-stage embedding. Experimental study is carried out using several images, and the results are compared with well-known methods in the literature. The results clearly highlight that the proposed algorithm can hide more data with less distortion.
Fragile and Blind Reversible Watermarking Method for Color Images using 4-Level DWT
P.Vamshidhar
International Journal of Computer Trends and Technology , 2011,
Abstract: Digital watermarking algorithms are widely applied to digital color image for ownership protection and tampering detection. Digital watermarking is the process of reversibly or irreversibly embedding information into a digital signal. Blind reversible watermarking has an additional advantage of recovering the image which is same as the original image pixel by pixel, after the image is authenticated. A fragile watermark is distorted in the case of tampering, notifying an investigator upon extraction of potential malicious manipulation in the image. A new algorithm is suggested for reversible watermarking which makes use of difference expansion concept in this paper. In the suggested algorithm, 4-level DWT of the input color image is calculated and the watermark bits are embedded in the transformed coefficients which don’t cause any overflow or underflow. The result for embedding up to 8 watermark bits per coefficient is presented. The complete VLSI implementation of watermark embedding and extraction is presented on the FPGA SPARTAN 3E board
A Novel Fractional-Discrete-Cosine-Transform-Based Reversible Watermarking for Healthcare Information Management Systems
Lu-Ting Ko,Jwu-E Chen,Yaw-Shih Shieh,Massimo Scalia,Tze-Yun Sung
Mathematical Problems in Engineering , 2012, DOI: 10.1155/2012/757018
Abstract: Digital watermarking is a good tool for healthcare information management systems. The well-known quantization-index-modulation- (QIM-) based watermarking has its limitations as the host image will be destroyed; however, the recovery of medical image is essential to avoid misdiagnosis. A transparent yet reversible watermarking algorithm is required for medical image applications. In this paper, we propose a fractional-discrete-cosine-transform- (FDCT-) based watermarking to exactly reconstruct the host image. Experimental results show that the FDCT-based watermarking is preferable to the QIM-based watermarking for the medical image applications.
Improved Bit Rate Control for Real-Time MPEG Watermarking  [cached]
Pranata Sugiri,Wahadaniah Viktor,Guan Yong Liang,Chua Hock Chuan
EURASIP Journal on Advances in Signal Processing , 2004,
Abstract: The alteration of compressed video bitstream due to embedding of digital watermark tends to produce unpredictable video bit rate variations which may in turn lead to video playback buffer overflow/underflow or transmission bandwidth violation problems. This paper presents a novel bit rate control technique for real-time MPEG watermarking applications. In our experiments, spread spectrum watermarks are embedded in the quantized DCT domain without requantization and motion reestimation to achieve fast watermarking. The proposed bit rate control scheme evaluates the combined bit lengths of a set of multiple watermarked VLC codewords, and successively replaces watermarked VLC codewords having the largest increase in bit length with their corresponding unmarked VLC codewords until a target bit length is achieved. The proposed method offers flexibility and scalability, which are neglected by similar works reported in the literature. Experimental results show that the proposed bit rate control scheme is effective in meeting the bit rate targets and capable of improving the watermark detection robustness for different video contents compressed at different bit rates.
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