Abstract:

Image tampering will destroy the light coherence of natural images. In order to ensure the security of image content, this paper presents a blind identification method based on the consistency of illuminant direction to identify the image authenticity. In accordance with the error function between the measured intensity and calculated intensity, and the regularization terms for different source models, this method estimates the illuminant direction for images of different source models. Analyzing if the illumination directions between different objects and background in one image are consistent to determine whether the image has been tampered with. Experimental results show that the correct detection rates for blind identification technology for digital images based on infinite light source model has reached up to 81.8%. In addition, experiments also show the effectiveness of blind identification base on local light source and composite light sources.

Key words: image tampering, illuminant direction, blind identification, image authenticity