Document images from mobile phone cameras and digital cameras suffer from geometric distortion; therefore distortion correction is desired for better character recognition. We propose a method to calculate the aspect ratio of planar documents using 3D perspective projection of quadrangles without using vanishing points. The proposed method is based on estimation of direction of a pair of parall...

This work investigates functional source coding problems with maximal distortion, motivated by approximate function computation in many modern applications. The distortion treats imprecise reconstruction of a value as good perfect if it deviates less than tolerance level, while treating that differs more level failure. Using geometric understanding the we propose hypergraph-based scheme for is ...

Some issues on direct-projected augmented reality (DirectAR) are addressed: the projection may be geometrically distorted due to the non-planar surface (geometric distortion); the projection cannot be seen to user as intended because the position of the projector is not the same as that of the user’s viewpoint (viewpoint-ignorant projection); the projection may be modulated by surface color (ra...

Three sufficient conditions are proposed for an iso-parametric finite element formulation to be immune to mesh-distortion effects, even for extremely distorted element geometries for which the Jacobian geometric mapping goes negative! Illustrative element formulations are presented to test the sufficiency of the proposed conditions. Numerical results confirm that the illustrative elements are i...