scholarly journals LDPC coded hybrid discrete cosine transform and Fejér–Korovkin wavelet transform-based SC-FDMA for image communication

Array ◽  
2021 ◽  
Vol 12 ◽  
pp. 100107
Author(s):  
Rafiul Kadir ◽  
Ritu Saha ◽  
Md. Mueid Akhter ◽  
Md. Abdul Awal ◽  
Mohammad Ismat Kadir
Keyword(s):  
Wavelet Transform ◽  
Discrete Cosine Transform ◽  
Cosine Transform ◽  
Image Communication

LWT-DCT based Image Watermarking Scheme using Normalized SVD

2020 ◽  
Vol 13 ◽  
Author(s):  
Rahul Dixit ◽  
Amita Nandal ◽  
Arvind Dhaka ◽  
Vardan Agarwal ◽  
Yohan Varghese
Keyword(s):  
Wavelet Transform ◽  
Singular Value Decomposition ◽  
Discrete Cosine Transform ◽  
Image Watermarking ◽  
Singular Value ◽  
Cover Image ◽  
Lifting Wavelet Transform ◽  
Cosine Transform ◽  
Lifting Wavelet ◽  
Value Decomposition

Background: Nowadays information security is one of the biggest issues of social networks. The multimedia data can be tampered with, and the attackers can then claim its ownership. Image watermarking is a technique that is used for copyright protection and authentication of multimedia. Objective: We aim to create a new and more robust image watermarking technique to prevent illegal copying, editing and distribution of media. Method : The watermarking technique proposed in this paper is non-blind and employs Lifting Wavelet Transform on the cover image to decompose the image into four coefficient matrices. Then Discrete Cosine Transform is applied which separates a selected coefficient matrix into different frequencies and later Singular Value Decomposition is applied. Singular Value Decomposition is also applied to the watermarking image and it is added to the singular matrix of the cover image which is then normalized followed by the inverse Singular Value Decomposition, inverse Discrete Cosine Transform and inverse Lifting Wavelet Transform respectively to obtain an embedded image. Normalization is proposed as an alternative to the traditional scaling factor. Results: Our technique is tested against attacks like rotation, resizing, cropping, noise addition and filtering. The performance comparison is evaluated based on Peak Signal to Noise Ratio, Structural Similarity Index Measure, and Normalized Cross-Correlation. Conclusion: The experimental results prove that the proposed method performs better than other state-of-the-art techniques and can be used to protect multimedia ownership.

Image Compression Using Discrete Cosine Transform & Discrete Wavelet Transform

2013 ◽  
Vol 002 (001) ◽  
pp. 25-27 ◽  
Author(s):  
Anurag Tiwari ◽  
◽  
Payal Chandrakant ◽  
Trip ti ◽  
Surabhi Chaudhary ◽  
...  
Keyword(s):  
Wavelet Transform ◽  
Image Compression ◽  
Discrete Wavelet Transform ◽  
Discrete Cosine Transform ◽  
Discrete Wavelet ◽  
Cosine Transform

scholarly journals Comparative analysis of medical images watermarking methods

2020 ◽  
Vol 17 ◽  
pp. 379-383
Author(s):  
Sylwia Duda ◽  
Dominik Fijałek ◽  
Grzegorz Kozieł
Keyword(s):  
Wavelet Transform ◽  
Comparative Analysis ◽  
Singular Value Decomposition ◽  
Discrete Cosine Transform ◽  
Medical Images ◽  
Singular Value ◽  
Integer Wavelet Transform ◽  
Cosine Transform ◽  
Value Decomposition ◽  
Integer Wavelet

The article is devoted to the analysis of watermarking algorithms in terms of their use in marking medical images. The algorithms based on the Integer Wavelet Transform (IWT), Discrete Cosine Transform (DCT), and Singular Value Decomposition (SVD) were compared. The algorithms were implemented using the combinations: IWT, IWT-DCT, and IWT-SVD. As part of the research, the level of disturbances caused by embedding the watermark was checked using subjective and objective methods. The attack resistance of the watermarked images was tested and the steganographic capacity was measured. All algorithms are based on IWT, however, each has different advantages. The algorithm based on the IWT showed the highest capacity. The most resistant to attacks is IWT-SVD, and the lowest level of interference was obtained for the IWT-DCT algorithm.

A DCT Fractional bit replacement based Dual Watermarking Algorithm for Image Authentication

2020 ◽  
Vol 13 ◽  
Author(s):  
Rahul Dixit ◽  
Amita Nandal ◽  
Arvind Dhaka ◽  
Yohan Varghese ◽  
Vardan Agarwal
Keyword(s):  
Wavelet Transform ◽  
Singular Value Decomposition ◽  
Discrete Wavelet Transform ◽  
Discrete Cosine Transform ◽  
Singular Value ◽  
Discrete Wavelet ◽  
Cosine Transform ◽  
Robust Watermark ◽  
Dual Watermarking ◽  
Value Decomposition

: Watermarking is a process of embedding a message inside a digital signal like an image, video or text. It is used for several key reasons such as authenticity verification, ownership recognition and hidden communication. In this paper, we discuss about image watermarking, where secret messages are stored in images. Introduction: We propose a dual watermarking approach, which is based on Discrete Cosine Transform, Discrete Wavelet Transform and Singular Value Decomposition methods. This paper considers one watermark as robust and other water mark as fragile. Method: The robust watermark is embedded in Discrete Wavelet Transform- Singular Value Decomposition - domain and is used to transmit hidden messages. The fragile watermark is embedded in Discrete Cosine Transform domain and is used for verification of secret message of the robust watermark. The proposed algorithm is tested in the experimental results section and shows promising results against denoising, rotation, translation and cropping attacks. Result: The results show that the performance of the proposed algorithm in terms of mean squared error, structural similarity and peak signal to noise ratio is S4considerable as compared with the existing methods. Discussion: We present the comparison results with Himanshu et. al. in table 10, from which we can see that our method performs better with gaussian noise and rotational attack only lacking with Salt and Pepper noise. Fig. 7 and Fig. 8, in terms of resulting PSNR shows the variation of noise variance and degree of rotation. From the graphs it is evident that out method performs better against Gaussian and rotational attack. Conclusion: In this paper a dual watermarking method is proposed in which one watermark is fragile which is called as authentication watermark whereas the other watermark is robust and is called as the information watermark. The authentication watermark is embedded in the fractional part of DCT domain in the cover image and the information watermark is embedded in the diagonal vector of the LL sub-band.

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