A watermarking scheme based on digital images' signatures

2011 ◽  
Author(s):  
Chunxing Wang ◽  
Xiaomei Zhuang
Keyword(s):  
Digital Images ◽  
Watermarking Scheme

An Adaptive Curvelet Based Semi-Fragile Watermarking Scheme for Effective and Intelligent Tampering Classification and Recovery of Digital Images

2018 ◽  
Vol 5 (2) ◽  
pp. 69-94
Author(s):  
K R Chetan ◽  
S Nirmala
Keyword(s):  
Digital Images ◽  
Similarity Index ◽  
Curvelet Transform ◽  
Input Image ◽  
Tamper Detection ◽  
Fragile Watermarking ◽  
Feature Similarity ◽  
Feature Similarity Index ◽  
Index Value ◽  
Watermarking Scheme

A novel adaptive semi-fragile watermarking scheme for tamper detection and recovery of digital images is proposed in this paper. This scheme involves embedding of content and chroma watermarks generated from the first level Discrete Curvelet Transform (DCLT) coarse coefficients. Embedding is performed by quantizing the first level coarse DCLT coefficients of the input image and amount of quantization is intelligently decided based on the energy contribution of the coefficients. During watermark extraction, a tampered matrix is generated by comparing the feature similarity index value between each block of extracted and generated watermarks. The tampered objects are subsequently identified and an intelligent report is formed based on their severity classes. The recovery of the tampered objects is performed using the generated DCLT coefficients from luminance and chrominance components of the watermarked image. Results reveal that the proposed method outperforms existing method in terms of tamper detection and recovery of digital images.

Using Watermarking Techniques to Prove Rightful Ownership of Web Images

2014 ◽  
pp. 130-141
Author(s):  
Abdallah Al-Tahan Al-Nu’aimi
Keyword(s):  
Standard Deviation ◽  
Digital Images ◽  
Evaluation Metrics ◽  
Colour Channel ◽  
Web Images ◽  
Objective Tests ◽  
Watermarking Scheme

This article introduces intelligent watermarking scheme to protect Web images from attackers who try to counterfeit the copyright to damage the rightful ownership. Using secret signs and logos that are embedded within the digital images, the technique can investigate technically the ownership claim. Also, the nature of each individual image is taken into consideration which gives more reliable results. The colour channel used was chosen depending on the value of its standard deviation to compromise between robustness and invisibility of the watermarks. Several types of test images, logos, attacks and evaluation metrics were used to examine the performance of the techniques used. Subjective and objective tests were used to check visually and mathematically the solidity and weakness of the used scheme.

Sign in / Sign up

Export Citation Format

Share Document