Estimation of lighting environment for exposing image splicing forgeries

Abstract

This paper proposes a novel image forensics technique to detect splicing forgeries in digital images. The method is applicable to images containing two or more persons, where the near frontal views of the faces are available. Firstly, a low-dimensional lighting model is created from a set of front pose face images of a single individual under different directional lighting environments. For this, the set of images is decomposed using principal component analysis. This low-dimensional model, which captures the lighting variation in faces, is then used to estimate the lighting environment (LE) from a given near front pose face image. In a spliced image, the LE estimated from the spliced face will be different from that estimated from the original faces. Therefore, finding the inconsistencies among the LEs estimated from different faces could reveal the splicing forgery. The experimental results on Yale Face Database B and a set of authentic and forged real-life images show the efficacy of the proposed method.