Learn More
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)
Image hashing function maps an image into a bit string which can be used to authenticate the originality of the image. In this paper, we propose a perceptual image hashing scheme that is secure and robust to visually insignificant changes but fragile enough to detect and precisely locate malicious attacks. The proposed image hashing method is based on the(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)
For original paper see J. Shich, D.Lou and M. Chang, ibid., vol.28, p.428-440, (2006). In a recent paper, a robust water-marking approach for hiding grayscale image watermark into digital images based on SVD (singular value decomposition) is proposed by Shich et al. This comment demonstrates that the high robustness of the proposed scheme against various(More)
Peptides and small molecules produced by both the plant pathogen Phytophthora and host plants in the apoplastic space mediate the relationship between the interplaying organisms. Various Phytophthora apoplastic effectors, including small cysteine-rich (SCR) secretory proteins, have been identified, but their roles during interaction remain to be determined.(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)