中文摘要：

图像技术的发展,使其成为图像篡改的双刃剑.如何对已篡改的图像进行数字取证成为当前研究热点之一.本文对基于JPEG特性的图像被动取证技术进行分析,根据JPEG图像被动取证技术中不同算法所选用的特征量,将现有的技术方法分为两类：针对JPEG重压缩的被动取证和针对JPEG重采样的被动取证.详细分析了上述两类方法各自的特点及对应的优缺点,指出当前基于JPEG特性的图像被动取证的技术的不足之处,并对相关技术的未来发展方向进行了展望.

英文摘要：

The development of image technology has become a double-edged sword of image tampering. How to obtain evidence of image tampering has become one of the present research hotspot. This paper analyses the passive forensics technology for JPEG images based on the characteristics of JPEG. Ac- cording to the feature used in the JPEG images passive forensics, the existing techniques are divided into to categories： blind forensic techniques based on double-JPEG compression and blind forensic tech- niques based on double-JPEG resample. The characteristics and corresponding advantages and disad- vantages of the two methods are analyzed in detail. In the end, the inadequacy of the existing passive forensics technology based on the characteristics of JPEG is stated and the future of the technology is looked into.