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Many existing source camera classification methods involve either training a classifier or computing the reference pattern noise of a camera, which means a set of images of known origins have to be pre-acquired. However, such requirement can not always be satisfied in real-world forensic applications. In this work, we propose a graph based approach that(More)
This paper investigates the digital forensic problem of determining whether an image has been produced by a specific digital camera. We employ the binary hypothesis testing scheme to detect the presence of photo-response non-uniformity(PRNU) in the image. The main challenge of this scheme is the extremely weak amount of PRNU in the observed noise residual.(More)
Geometry processing has made ample use of discrete representations of tangent vector fields and antisymmetric tensors (i.e., forms) on triangulations. Symmetric 2-tensors, while crucial in the definition of inner products and elliptic operators, have received only limited attention. They are often discretized by first defining a coordinate system per(More)
A novel two-stage scheme of pornographic image detection is proposed in this paper. Specifically, we first apply the content-based image retrieval technique to find out whether human are present in the images. Then a detailed skin color analysis is performed to affirm the presence of pornographic content in the images. Experimental results show that the(More)
We present a model-reduced variational Eulerian integrator for incompressible fluids, which combines the efficiency gains of dimension reduction, the qualitative robustness of coarse spatial and temporal resolutions of geometric integrators, and the simplicity of sub-grid accurate boundary conditions on regular grids to deal with arbitrarily-shaped domains.(More)
In this article, we introduce a discrete definition of connection on simplicial manifolds, involving closed-form continuous expressions within simplices and finite rotations across simplices. The finite-dimensional parameters of this connection are optimally computed by minimizing a quadratic measure of the deviation to the (discontinuous) Levi-Civita(More)