Blind Image Watermarking for Localization and Restoration of Color Images

Rishi Sinhal,Irshad Ahmad Ansari,Chang Wook Ahn

doi:10.1109/access.2020.3035428

Abstract

Digital images have become easy to generate and share with tremendous growth in communication technology. Therefore, the threat of forgery and tampering in digital images has also been increased. This study proposes a blind fragile watermarking scheme for color images to provide efficient image tamper detection and self-recovery. A secret key based pseudo random binary sequence is used as a fragile watermark for tamper detection. Likewise, the recovery information is preserved in a randomized manner using a secret key. During embedding, each channel of the RGB image is divided into non-overlapping 2 × 4 size blocks. Each block is then watermarked using a LSB (least significant bit) replacement process in 9-base notation structure. The watermark sequence (i.e. 12-bit) for each block contains 6-bits from the fragile watermark and concatenated with the recovery information (i.e. 6 MSB (most significant bit) of block's mean value) of a different block. The experimental results confirm that the scheme is highly efficient to locate tampered region and recover the original image even in case of serious tampering. The scheme offers nearly 99% accurate tamper detection and significant recovery of tampered images (up to 80% tampering rate). Comparative results prove the significance and superiority of the scheme over existing schemes.

Highlights

At present, it is very common to access and use digital multimedia data available over internet
Tamper detection and localization of digital images have become a prime concern to protect the authenticity of images [4]
Digital image watermarking is widely used to detect tampering in the images [5]

Summary

Introduction

It is very common to access and use digital multimedia data available over internet. Digital image watermarking is widely used to detect tampering in the images [5]. Digital watermarking is used for a number of applications like copyright protection, tamper detection, self-recovery etc. There is no need of host and watermark at the time of extraction in blind watermarking except the secret key [9]. In the semi-blind scheme, the information of the watermark signal and the secret key is needed during extraction. The non-blind watermarking technique needs both host and watermark along with the secret key for the extraction process. In another way, watermarking can be classified as robust, fragile or semifragile based on the nature of watermark information [10].

Methods

Results

Conclusion