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Natural images in the colour space YUV have been observed to have a non-Gaussian, heavy tailed distribution (called `sparse') when the filter ??(U)(r) = U(r) - s??N(r)?? w(Y)rsU(s), is applied to the chromacity channel U (and equivalently to V), where w is a weighting function constructed from the intensity component Y. In this paper we develop Bayesian analysis of the colorization problem using the...
Due to the spherical shape nature of retina and the illumination effect, detecting bright lesions in a retinal image is a challenging problem. Existing methods depend heavily on a prior knowledge about lesions, which either a user-defined parameter is employed or a supervised learning technique is adopted to estimate the parameter. In this paper, a novel sharpness measure is proposed, which indicates...
This paper proposed an evolutionary method to optimizing the cosine window family by using Differential Evolution (DE). First, the classic cosine windows such as Hamming window and Blackman window are optimized. Results show better performance in terms of side-lobe level and roll-off ratio for the same main-lobe width. Then, a series of optimized six order cosine windows are provided and their performances...
3D shape matching based on meshed surfaces can be formulated as an energy function minimisation problem under a Markov random field (MRF) framework. However, to solve such a global optimisation problem is NP-hard. So research mainly focuses on approximation algorithms. One of the best known is belief propagation (BP), which has shown success in early vision and many other practical applications. In...
This paper investigates the effect of foot shape on biped locomotion. In particular, we consider planar biped robots whose feet are composed of curved surfaces at toe and heel and a flat section between them. We developed an algorithm that can optimize the gait pattern for a set of foot shape, walk speed and step length. The optimization is formulated based on the rigid-body and collision dynamics...
Subspace-based optimization methods (SOM) for locating scatterers have been reported recently. The positions and shapes of scatterers are reconstructed by checking the contour of permittivity. Background conditions, including the shape of domain of interest, aperture, and frequency of incident wave, have an influence on the process of permittivity reconstruction. We examine the domain shape effect...
Local convergence is a limitation of many optimization approaches for multimodal functions. For hybrid model learning, this can mean a compromise in accuracy. We develop an approach for learning the model parameters of hybrid discrete-continuous systems that avoids getting stuck in locally optimal solutions. We present an algorithm that implements this approach that 1) iteratively learns the locations...
This paper discusses an optimal control approach for the registration of image time-series (growth modeling). It combines and augments work on an optimal control formulation to optical flow with theory from large-displacement diffeomorphic image registration. The unification of the two viewpoints leads to (i) a more efficient computation of the gradient of the optimization problem, (ii) an easier...
An optimization technique is proposed for the outline capture of planar images. The overall technique has various phases including extracting outlines of images, detecting corner points from the detected outline, and curve fitting. Linear and conic interpolation methods have been used for vectorization. The idea of multilevel coordinate search has been used to optimize the shape parameters in the...
There are extra equipments such as sonar arrays, electronic devises, antennas and video cameras which are mounted of the surface of the submarines' hull. These equipments create drag and interfering turbulent noises. Created noises and also vibrations cause failure for operating and monitoring these devices. The process of design and optimization the Case for such these devises is presented in order...
In this paper we propose a new method for local structural alignment of protein surfaces based on global optimization techniques. The method can be applied to the comparison and recognition of protein binding sites, a relevant problem in drug design. Given the three-dimensional structures of two proteins, we are interested in finding the isometric transformation (rotation plus translation) that best...
A direct approach for parametric estimation of 2D affine deformations between compound shapes is proposed. It provides the result as a least-square solution of a linear system of equations. The basic idea is to fit Gaussian densities over the objects yielding covariant functions, which preserves the effect of the unknown transformation. Based on these functions, linear equations are constructed by...
In this paper, we consider the feature correspondence task as a graph matching problem. Our approach tends to maximize a similarity objective function, which consists of not only the feature vectors but also their corresponding constrained global spatial structures, by a new polynomial-time approximate optimization algorithm. This algorithm allows every node in a smaller graph to potentially be linked...
In this paper, the crowd counting and segmentation problem is formulated as a maximum a posterior problem, in which 3D human shape models are designed and matched with image evidence provided by foreground/background separation and probability of boundary. The solution is obtained by considering only the human candidates that are possible to be un-occluded in each iteration, and then applying on them...
The problem of estimating the three-dimensional (3D) geometry of an object from a sequence of images obtained at different focus settings is called shape from focus (SFF). The conventional SFF methods apply focus measure operator at each pixel using neighboring pixels in the same image frame. However, for an object with complex geometry, such methods cannot compute accurate focus level of a pixel,...
A novel approach is proposed to estimate the parameters of a diffeomorphism that aligns two binary images. Classical approaches usually define a cost function based on a similarity metric and then find the solution via optimization. Herein, we trace back the problem to the solution of a system of nonlinear equations which directly provides the parameters of the aligning transformation. The proposed...
The optimization of baseband processing is proposed to compensate for high power amplifier (HPA) nonlinear distortion and channel noise, and to meet an output spectral constraint without the use of a spectral containment filter. Global compensation data predistortion with memory and square root raised cosine pulse shaping are employed, and the spectral regrowth and nonlinear intersymbol interference...
The research of autobody lightweight technology is an important mainstream in the autobody design. In this paper A FEM model for the unitary body of a home-made bus is established .Then optimization design variables are determined through stiffness sensitivity analysis and by using finite element analysis software, an optimization is conducted, based on which a lightweighting scheme is put forward...
There are many kinds of deformable objects in our living life. Some of them such as human tissues, human organs, and food exhibit rheological behaviors when they are subject to external force. In surgery simulation and food engineering, we need to simulate or control such behaviors. In this paper, four-element model associated with finite element (FE) method was employed to model rheological deformation...
This paper presents an approach to time-optimal kinodynamic motion planning for a mobile robot. A global path planner is used to generate collision-free straight-line paths from the robot's position to a given goal location. With waypoints of this path, an initial trajectory is generated which defines the planned position of the robot over time. A velocity profile is computed that accounts for constraints...
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