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—In this paper, we propose a robust framework for building extraction in visible band images. We first get an initial classification of the pixels based on an unsupervised presegmen-tation. Then, we develop a novel conditional random field (CRF) formulation to achieve accurate rooftops extraction, which incorporates pixel-level information and segment-level(More)
Decomposition and segmentation of the objects represented by point cloud data become increasingly important for purposes like shape analysis and object recognition. In this paper, we propose a perception based approach to segment point cloud into distinct parts, and the decomposition is made possible of spatially close but geodetically distant parts.(More)
Point cloud is a basic description of discrete shape information. Parameterization of unorganized points is important for shape analysis and shape reconstruction of natural objects. In this paper we present a new algorithm for global parameterization of an unorganized point cloud and its application to the meshing of the cloud. Our method is guided by(More)
—This paper presents a method to extract rooftops from aerial images with only visible red, green, and blue bands of data. In particular, it does not require near-infrared data, lidar, or multiple viewpoints. The proposed method uses shadows in the image in order to detect buildings and to determine a set of constraints on which parts can or cannot be(More)
Point data are basic media for shape information acquisition and representation. A new approach is presented for global parameterization of unorganized point data and application to the meshing of point models with noises. While most of recent researches focus on quadrangulation of mesh models, it is extended to point models in this work, so as to loosely(More)
We derive macroscopic equations of motion for the slowly varying electric field amplitude in three-dimensional active nonlinear optical nanostructures. We show that the microscopic Maxwell equations and polarization dynamics can be simplified to a macroscopic one-dimensional problem in the direction of group velocity. For a three-level active material, we(More)
The development of photonic nano-structures can strongly benefit from full-field electromagnetic (EM) simulations. To this end, geometrical flexibility and accurate material modelling are crucial requirements set on the simulation method. This paper introduces a modular implementation of dispersive materials for time-domain EM simulations with focus on the(More)
In the past several years, domain decomposition has been a very popular topic, partly motivated by the potential of parallelization. While a large body of theory and algorithms have been developed for model elliptic problems, they are only recently starting to be tested on realistic applications. In this paper, after a brief introduction an survey of the(More)