The Research Of Digital Image Forensics Based On Optical Properties

With the rapid development of computer network and image processing technology, people can easily tamper with the contents of the image without any trace. As result, the authenticity of digital image has attracted the wide attention of relevant institutions in various countries. Digital image forensics technology make analysis in forgery, tampering and confidentiality of digital image including identification authentication technology as one of the branch of information security technology. The paper simply introduces the basis research and development present situation of digital image forensics technology. Based on the further study of the current model, the improved algorithm employs new analysis method on source location and optical properties consistency.First of all, this paper employs the optical properties including the shadows corresponding to objects in the image and shading feature from the point light source, and makes constraints equations in the limited analysis interface to determine whether a shadow constraint conditions is consistent or not. At the same time, introduce the information for the objects’ shadow in the image corresponding at the limited constraints analysis interface, and then judge whether the constraint conditions of the shadow wedge.Secondly, according to the shading feature introduced on the basis of above research, the improved algorithm introduces the shading feature by increasing the dimension of linear constraint equations. Make the shadow wedge as research emphasis, and makes the correlation analysis with the software of statistical data to determine the correlation of these parameters and obtain the linear expressions about the parameters, and then obtain the linear representation for the wedge in related parameters.Finally, the geometric relationship between the various parameters to be defined through the establishment of a multidimensional inequality wedge and texture parameters, and estimate the parameters of the effective range of the wedge-shaped shadow, even in the infinite analysis interface can be obtained preliminary test results. Meanwhile, the method of introduction of image coordinates to determine the parameters of the wedge boundary coordinates, and verify thecorrectness of the algorithm comparison through the relationship between these parameters, so that the improved algorithm has higher applicability.The article finally, for improved detection algorithm simulation, the image infinity point light source and a local point source produced were detected and analyzed the test results, while improving the accuracy of the calculation and statistical algorithms to detect image is compared with the previous algorithm. Improved the algorithm has higher detection rate and stability.Meanwhile, the improved algorithm in this paper is extended to the digital images contain more complex lighting conditions, a preliminary discussion on the digital image detection algorithm’s applicability and accuracy. Finally, the paper summarizes the work and discuss the future direction of this research and development related fields.