A reversible watermarking scheme for two-dimensional CAD engineering graphics based on improved difference expansion

2011 ◽  
Vol 43 (8) ◽  
pp. 1018-1024 ◽  
Author(s):  
Fei Peng ◽  
Yu-zhou Lei ◽  
Min Long ◽  
Xing-ming Sun
Keyword(s):  
Reversible Watermarking ◽  
Two Dimensional ◽  
Difference Expansion ◽  
Engineering Graphics ◽  
Watermarking Scheme

An Improved Reversible Watermarking Algorithm in Wavelet Domain for Two-Dimensional CAD Engineering Graphics

2013 ◽  
Vol 655-657 ◽  
pp. 349-354
Author(s):  
Xiaoli Tu ◽  
Xue Mei Jiang ◽  
Xiao Mei Zhang
Keyword(s):  
Reversible Watermarking ◽  
Digital Design ◽  
Two Dimensional ◽  
Wavelet Domain ◽  
Engineering Graphics ◽  
Affine Transform ◽  
Previous Algorithm ◽  
Chaos Sequence ◽  
Index Modulation ◽  
Good Visibility

With the development of digital design and processing and the explosive growth of the demand for two-dimensional CAD engineering graphics, more attention has been paid on the security and the copyright issues of engineering graphics. In this paper, an improved reversible watermarking algorithm in wavelet domain for two-dimensional CAD engineering graphics is proposed. Firstly, the watermark information is preprocessed by compound chaos sequence. And then, block the graphic and extract all vertexes in each blocks of the 2D CAD engineering graphics, Log-polar Mapping (LPM) and wavelet transform are done to them respectively to achieve the invariance of affine transform. Finally, the encrypted watermark is embedded into detailed coefficients by using improved quantization index modulation (IQIM) scheme. Compared with the original previous algorithm, theoretical analysis and experimental results show that the proposed algorithm has not only good visibility and good reversibility, but also stronger robust against the attacks such as transformation, rotation, equal scaling and entity deleting, tampering or adding etc.

An Effective Reversible Watermarking for 2D CAD Engineering Graphics Based on Improved QIM

2011 ◽  
Vol 3 (1) ◽  
pp. 53-69 ◽  
Author(s):  
Fei Peng ◽  
Yu-Zhou Lei
Keyword(s):  
Reversible Watermarking ◽  
Experimental Results ◽  
Data Recovery ◽  
Quantization Index Modulation ◽  
Secret Key ◽  
Good Balance ◽  
Engineering Graphics ◽  
Watermarking Scheme ◽  
Index Modulation

Quantization index modulation (QIM) is widely used in watermarking, but QIM cannot be applied to reversible watermarking directly due to its inherent limitations. In this paper, an improvement is made to QIM to make it suitable for reversible watermarking. Based on the improved QIM (IQIM), a reversible watermarking scheme for 2D CAD engineering graphics is proposed. The relative amplitudes and the relative phases of entity vertices are used as hosts to carry the watermark, respectively, and the data recovery is controlled by a secret key. Experimental results indicate that the proposed scheme can strike a good balance between capacity, imperceptibility, robustness, security and complexity.

Half Difference Expansion Based Reversible Data Hiding Scheme for Medical Image Forensics

2020 ◽  
Vol 16 (4) ◽  
pp. 383-396
Author(s):  
Vazhora Malayil Manikandan ◽  
Nelapati Lava Prasad ◽  
Masilamani Vedhanayagam
Keyword(s):  
Medical Image ◽  
Medical Images ◽  
Visual Quality ◽  
Image Forensics ◽  
Reversible Watermarking ◽  
Difference Expansion ◽  
Data Set ◽  
Watermarking Scheme ◽  
Embedding Rate

Background: Medical image authentication is an important area which attempts to establish ownership authentication and data authentication of medical images. Aims: In this paper, we propose a new reversible watermarking scheme based on a novel half difference expansion technique for medical image forensics. Methods: Conventional difference expansion based reversible watermarking scheme generates watermarked images with less visual quality, and the embedding rate was considerably less due to the high probability of overflow or underflow. In the proposed scheme, the quality of the watermarked image has been improved by modifying the traditional difference expansion based watermarking scheme, half of the difference between two pixels will be expanded during watermarking. The modification of pixels during watermarking is limited by expanding half of the pixel difference, which helps to obtain watermarked images with better visual quality and improved embedding rate due to less chance of overflow or underflow during watermarking. We also propose a tamper detection localization process to detect the tampered regions from the watermarked image. Results: Experimental study of the proposed scheme on the standard medical images from Osrix medical image data set shows that the proposed watermarking scheme outperforms the existing schemes in terms of visual quality of the watermarked image and embedding rate. Conclusion: The overhead related to location map and parity information need to be addressed in future works to improve the proposed scheme.

A Semi-Fragile Reversible Watermarking for 2D CAD Engineering Graphics with Accurate Tampering Localization

2015 ◽  
Vol 7 (3) ◽  
pp. 1-18 ◽  
Author(s):  
Min Long ◽  
Yan Liu ◽  
Fei Peng
Keyword(s):  
High Precision ◽  
Reversible Watermarking ◽  
Relative Distance ◽  
Content Authentication ◽  
Difference Expansion ◽  
Engineering Graphics ◽  
Tampering Localization ◽  
Group Number ◽  
Integrity Protection ◽  
Uniform Scaling

A semi-fragile reversible watermarking algorithm for 2D CAD engineering graphics with accurate tampering localization is proposed. Firstly, all vertices in the 2D CAD engineering graphics are extracted and partitioned into groups. After that, the relative distance of these vertices are calculated, and the assigned group number is used as watermark. Finally, the watermark is embedded into the factor of relative distance by using an improved difference expansion. Experimental results and analysis show that the proposed algorithm can obtain a large capacity, good invisibility, and robust against translation, rotation, and uniform scaling. At the same time, it can detect malicious attacks such as entity modification, addition and deletion, and can locate the tampering areas with a high precision. As for the watermarked 2D CAD engineering graphics passing authentication, the original 2D CAD engineering graphics can be completely recovered. It has great potential in the application of integrity protection and content authentication of 2D CAD engineering graphics.

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