A novel adaptive digital image watermark algorithm is proposed. Fuzzy c-means clustering (FCM) is used to classify the original image blocks into two classes based on several characteristic parameters of human visua...A novel adaptive digital image watermark algorithm is proposed. Fuzzy c-means clustering (FCM) is used to classify the original image blocks into two classes based on several characteristic parameters of human visual system (HVS). One is suited for embedding a digital watermark, the other is not. So the appropriate blocks in an image are selected to embed the watermark. The wetermark is embedded in the middle-frequency part of the host image in conjunction with HVS and discrete cosine transform (DCT). The maximal watermark strength is fixed according to the frequency masking. In the same time, for the good performance, the watermark is modulated into a fractal modulation array. The simulation results show that we can remarkably extract the hiding watermark and the algorithm can achieve good robustness with common signal distortion or geometric distortion and the quality of the watermarked image is guaranteed.展开更多
Rotation,scaling and translation(RST)attacks can desynchronize watermark detection,which causes failure in many watermarking systems.In this paper,an image adaptive RST invariant watermark(AWPZM)is proposed by using t...Rotation,scaling and translation(RST)attacks can desynchronize watermark detection,which causes failure in many watermarking systems.In this paper,an image adaptive RST invariant watermark(AWPZM)is proposed by using the rotation invariant property of pseudo-Zernike moments(PZM)and odd-even quantization.PZM of the original image is computed first,and then those suitable for watermark generation are selected.Then,magnitudes of them are odd-even quantized to generate the watermark.In detection,a normalized hamming function is employed to determine the similarity of the watermark.Experimental results show its robustness to rotation and scaling.For traditional attacks,such as JPEG compression,added noise and filtering,the similarities are all above 0.95.展开更多
Quaternion algebra has been used to apply the fractional Fourier transform(FrFT)to color images in a comprehensive approach.However,the discrete fractional random transform(DFRNT)with adequate basic randomness remains...Quaternion algebra has been used to apply the fractional Fourier transform(FrFT)to color images in a comprehensive approach.However,the discrete fractional random transform(DFRNT)with adequate basic randomness remains to be examined.This paper presents a novel multistage privacy system for color medical images based on discrete quaternion fractional Fourier transform(DQFrFT)watermarking and three-dimensional chaotic logistic map(3D-CLM)encryption.First,we describe quaternion DFRNT(QDFRNT),which generalizes DFRNT to handle quaternion signals effectively,and then use QDFRNT to perform color medical image adaptive watermarking.To efficiently evaluate QDFRNT,this study derives the relationship between the QDFRNT of a quaternion signal and the four components of the DFRNT signal.Moreover,it uses the human vision system's(HVS)masking qualities of edge,texture,and color tone immediately from the color host image to adaptively modify the watermark strength for each block in the color medical image using the QDFRNT-based adaptive watermarking and support vector machine(SVM)techniques.The limitations of watermark embedding are also explained to conserve watermarking energy.Second,3D-CLM encryption is employed to improve the system's security and efficiency,allowing it to be used as a multistage privacy system.The proposed security system is effective against many types of channel noise attacks,according to simulation results.展开更多
基金Supported by the National Natural Science Foundation ofChina (10571127) the Doctoral Foundation of the Ministry of Educationof China (20040610004)
文摘A novel adaptive digital image watermark algorithm is proposed. Fuzzy c-means clustering (FCM) is used to classify the original image blocks into two classes based on several characteristic parameters of human visual system (HVS). One is suited for embedding a digital watermark, the other is not. So the appropriate blocks in an image are selected to embed the watermark. The wetermark is embedded in the middle-frequency part of the host image in conjunction with HVS and discrete cosine transform (DCT). The maximal watermark strength is fixed according to the frequency masking. In the same time, for the good performance, the watermark is modulated into a fractal modulation array. The simulation results show that we can remarkably extract the hiding watermark and the algorithm can achieve good robustness with common signal distortion or geometric distortion and the quality of the watermarked image is guaranteed.
基金This work was supported by the National Natural Science Foundation of China(Grant No.60572152)the Ph.D.Programs Foundation of the Ministry of Education of China(No.20060701004).
文摘Rotation,scaling and translation(RST)attacks can desynchronize watermark detection,which causes failure in many watermarking systems.In this paper,an image adaptive RST invariant watermark(AWPZM)is proposed by using the rotation invariant property of pseudo-Zernike moments(PZM)and odd-even quantization.PZM of the original image is computed first,and then those suitable for watermark generation are selected.Then,magnitudes of them are odd-even quantized to generate the watermark.In detection,a normalized hamming function is employed to determine the similarity of the watermark.Experimental results show its robustness to rotation and scaling.For traditional attacks,such as JPEG compression,added noise and filtering,the similarities are all above 0.95.
基金Project supported by the Princess Nourah bint Abdulrahman University Researchers Supporting Project(No.PNURSP2023R66)。
文摘Quaternion algebra has been used to apply the fractional Fourier transform(FrFT)to color images in a comprehensive approach.However,the discrete fractional random transform(DFRNT)with adequate basic randomness remains to be examined.This paper presents a novel multistage privacy system for color medical images based on discrete quaternion fractional Fourier transform(DQFrFT)watermarking and three-dimensional chaotic logistic map(3D-CLM)encryption.First,we describe quaternion DFRNT(QDFRNT),which generalizes DFRNT to handle quaternion signals effectively,and then use QDFRNT to perform color medical image adaptive watermarking.To efficiently evaluate QDFRNT,this study derives the relationship between the QDFRNT of a quaternion signal and the four components of the DFRNT signal.Moreover,it uses the human vision system's(HVS)masking qualities of edge,texture,and color tone immediately from the color host image to adaptively modify the watermark strength for each block in the color medical image using the QDFRNT-based adaptive watermarking and support vector machine(SVM)techniques.The limitations of watermark embedding are also explained to conserve watermarking energy.Second,3D-CLM encryption is employed to improve the system's security and efficiency,allowing it to be used as a multistage privacy system.The proposed security system is effective against many types of channel noise attacks,according to simulation results.