Exposing Image Forgery Using Lambert Model and Shadows

In view of the rapid development of the modern science and technology, image processing technology is also widely used in various fields. More and more digital images are tampered, which brings a lot of difficulties and troubles. This paper analyzes the shadows of objects which are produced by the point light source or the line light source, and makes a preliminary judgment by calculating the grey level. Based on Lambert illumination model and optical properties of consistency, this paper proposes a new technique to judge whether an image is tampered or not. At last, the experimental results are obtained by analyzing the shadows of a lot of images.