Color Image Authentication and Recovery via Adaptive Encoding

Chun-Hung Chen,Wen-Shyong Hsieh,Yuan-Liang Tang

doi:10.1155/2014/350753

Abstract

We describe an authentication and recovery scheme for color image protection based on adaptive encoding. The image blocks are categorized based on their contents and different encoding schemes are applied according to their types. Such adaptive encoding results in better image quality and more robust image authentication. The approximations of the luminance and chromatic channels are carefully calculated, and for the purpose of reducing the data size, differential coding is used to encode the channels with variable size according to the characteristic of the block. The recovery data which represents the approximation and the detail of the image is embedded for data protection. The necessary data is well protected by using error correcting coding and duplication. The experimental results demonstrate that our technique is able to identify and localize image tampering, while preserving high quality for both watermarked and recovered images.

Highlights

The revolution of digital technologies has brought many conveniences to our daily lives
We describe an authentication and recovery scheme for color image protection based on adaptive encoding
The experimental results demonstrate that our technique is able to identify and localize image tampering, while preserving high quality for both watermarked and recovered images

Summary

Introduction

The revolution of digital technologies has brought many conveniences to our daily lives. A statisticsbased rule is used to determine the validity of a block by considering its adjacent and mapping blocks This method provides a high detection rate for tampered regions, but they are recovered with only ordinary quality. The size of the recovery data of each block is determined by the block’s characteristics and the smooth blocks are encoded with less data than the textured ones Their method maintains high quality for watermarked images by effectively controlling the size of the embedding data. The data is extracted using dequantization and the inverse DCT Their method recovers the tamper areas with high image quality. All the extracted authentication data are taken into consideration and a majority-voting strategy is used to determine the validity of the image block Their method recovers the tampered regions with acceptable quality. The experimental results demonstrate that our technique is able to identify and localize image tampering, while preserving high quality for both watermarked and recovered images

The Proposed Method

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Experimental Results

Conclusion