A DCT-Based Image Authentication Approach with Attack Recovery

• Main Authors: Hsuan-An Ke, 柯炫安
• Other Authors: Chien-Chang Chen
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/60485867621787108372

碩士 === 玄奘大學 === 資訊科學學系碩士班 === 95 === Image authentication techniques verify the integrity of an image from malicious manipulations. Most image authentication methods treat all types of manipulation equally. However, with the increasing demand of JPEG images, a need arise in image authentication which could distinguish some acceptable manipulations like JPEG compression from malicious ones. In this thesis, we propose a DCT-based image authentication method which can detect authority and recover the malicious modification. The image feature codes are calculated from important DCT coefficients and then embedded into other DCT middle domain by our proposed quantization properties. The embedded information is tolerant to JPEG compression with quantization step less than two times of the pre-determined quantization step but is sensitive to other malicious attacks. The attacked blocks are indicated when verifying a watermarked image. Experimental results show that the attacked blocks can be recovered efficiently by the proposed approach.