关键词: 数字图像取证, 谱间相关性, 被动式图像鉴别, 小波分解

Abstract: How to discriminate between photorealistic computer generated images and real photographic images captured with a digital camera has become an important component of digital image forensics.To solve this problem，this paper presents a novel image authentication approach using spectral correlation between color planes in an image for forensic analysis.In single-CCD imaging systems，only one color component per pixel is captured，the missing two color values at the pixel are interpolated by CFA（Color Filter Array）.Demosaicked images by CFA interpolation exhibit higher spectral correlation between different color planes.In the suggested method，statistical spectral correlations between color components are exploited using discrete wavelet transform and normalized cross correlation to verify photographic images.Experimental results tested on the de facto standard Columbia dataset demonstrate that these features are effectual in capturing the differences between two kinds of images and the proposed method achieves promising accuracy in passive image authentication.

Key words: digital image forensics, spectral correlation, passive image authentication, wavelet decomposition