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Rotations, translations and symmetry detection for complexified curves

COMPUTER AIDED GEOMETRIC DESIGN 2008年第9期25卷 707-719页

作者： Lebmeir, Peter Richter-Gebert, Juergen Tech Univ Munich Dept Math D-85748 Garching Germany

A plane algebraic curve can be represented as the zero-set of a polynomial in rwo-or if one takes homogeneous coordinates: three-variables. The coefficients of the polynomial determine the curve uniquely. Thus features of the curve, like for instance rotation symmetry, must find their correspondence in the algebraic structure of the coefficients of the polynomial. In this article we will investigate how one can extract geometric curve features from the algebraic description of the curve. In particular, we will use a certain complex representation of polynomials introduced by (Tarel, J.-P., Cooper, D.B., 1998. A new complex basis for implicit polynomial curves and its simple exploitation for pose estimation and invariant recognition. In: conference on Computer vision and Pattern Recognition (CvPR'98), pp. 111-117;Unel, M., Wolovich, W.A., 1998. Complex representations of algebraic curves. In: International conference on image processing ICIP 1998, pp. 272-276), which is very appropriate for the task of feature detection. in this complex representation actions on the curve parameters induced by geometric rotations or translations of the plane become very simple. Invariant expressions in the complexified parameters and also normal forms are easily accessible. Furthermore this representation allows the detection of rotation symmetry simply by looking at the indices of all non-vanishing complex parameters. (C) 2008 Elsevier B.v. All rights reserved.

关键词： Zero set Curves homogeneous coordinates international conference algebra computer vision images Polynomial algebraic curve Rotational symmetry feature detections crop rotation Rotations complex parameter

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An Enhanced Segmentation of Blood vessels in Retinal images Using Contourlet

An Enhanced Segmentation of Blood Vessels in Retinal Images ...

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30th Annual International conference of the IEEE-Engineering-in-Medicine-and-Biology-Society

作者： Rezatofighi, S. H. Roodaki, A. Noubari, H. Ahmadi Univ British Columbia Dept Elect & Comp Engn Vancouver BC V5Z 1M9 Canada Univ Tehran Fac Elect & Comp Engn Control & Intelligent Proc Ctr Excellence Tehran Iran

ISBN: (纸本)9781424418145

Retinal images acquired using a fundus camera often contain low grey, low level contrast and are of low dynamic range. This may seriously affect the automatic segmentation stage and subsequent results;hence, it is necessary to carry-out preprocessing to improve image contrast results before segmentation. Here we present a new multi-scale method for retinal image contrast enhancement using Contourlet transform. In this paper, a combination of feature extraction approach which utilizes Local Binary Pattern (LBP), morphological method and spatial image processing is proposed for segmenting the retinal blood vessels in optic fundus images. Furthermore, performance of Adaptive Neuro-Fuzzy Inference System (ANFIS) and Multilayer Perceptron (MLP) is investigated in the classification section. The performance of the proposed algorithm is tested on the publicly available DRIvE database. The results are numerically assessed for different proposed algorithms.

关键词： Local binary pattern

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High throughput SAFT for an experimental USCT system as MATLAB implementation with use of SIMD CPU instructions

High throughput SAFT for an experimental USCT system as MATL...

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Medical Imaging 2008 conference

作者： Zapf, M. Schwarzenberg, G. F. Ruiter, N. v. Forschungszentrum Karlsruhe D-76021 Karlsruhe Germany

ISBN: (纸本)9780819471048

At Forschungszentrum Karlsruhe an Ultrasound Computer Tomography system USCT) is under development for early breast cancer detection. To detect morphological indicators in sub-millimeter resolution, the visualization is based on a SAFT algorithm (synthetic aperture focusing technique). The current 3D demonstrator system consists of approx. 2000 transducers, which are arranged in layers on a cylinder of 18 cm diameter and 15 cm height. With 3.5 millions of acquired raw data sets and up to one billion voxels for an image, a reconstruction may last up to months. In this work a performance optimized SAFT algorithm is developed. The used software environment is MathWorks' MATLAB. Several approaches were analyzed: a plain M-code (MATLAB's native language), an optimized M-code, a C-code implementation, and a low-level assembler implementation. The fastest found solution uses an SIMD enhanced assembler code wrapped in the C-interface of MATLAB. Additionally a 10 % speed up is gained by reducing the function call overhead. The overall speed up is more than one order of magnitude. The resulting computational efficiency is near the theoretical optimum. The reconstruction time is significantly reduced without losing MATLAB's comfortable development environment.

关键词： SAFT ellipsoidal backprojection image reconstruction performance MATLAB

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Fast digitizing of 3D shapes by automatic alignment of multiple range maps

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3rd International conference on Advanced Research in virtual and Rapid Prototyping

作者： Barone, S. Paoli, A. Razionale, A. v. Univ Pisa Dept Mech Nucl & Prod Engn Pisa Italy

ISBN: (纸本)9780415416023

Range maps registration still represents one of the most time consuming phases in the digitization of 3D shapes due to the high user intervention required. The traditional approaches are, in fact, based on manual rough alignments, followed by ICP refining techniques. On the other hand, existing unattended methodologies, based on the automatic searching for correspondent morphological singularities on adjacent point clouds, do not seem to guarantee sufficient robustness and flexibility in the fast reconstruction of target objects. This paper presents a methodology to acquire free-form shapes by combining a 3D stereo vision system and a fully automatic range maps registration process. The automatic alignment is carried out without any assumptions about the initial positions of the point clouds and is based on the automatic detection of fiducial markers, located on the surface object, by processing grey intensity images.

关键词： Stereo image processing

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An efficient method to produce clonal colonies of cancer cells using Laser Enabled Analysis and processing (LEAP)

An efficient method to produce clonal colonies of cancer cel...

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conference on Imaging, Manipulation and Analysis of Biomolecules, Cells, and Tissues vI

作者： Zordan, Michael Fatig, Ray Reece, Lisa Davisson, v. Jo Leary, James Purdue Univ Weldon Sch Biomed Engn W Lafayette IN 47907 USA Purdue Univ Bindley Biosci Ctr W Lafayette IN 47907 USA Purdue Univ Sch Vet Med Dept Basic Med Sci W Lafayette IN 47907 USA Purdue Univ Dept Med Chem & Mol Pharmacol W Lafayette IN 47907 USA Purdue Univ Birck Nanotechnol Ctr W Lafayette IN 47907 USA

ISBN: (纸本)9780819470348

Many in vitro studies require a pure clonal population of cells that derive from a single cell. Traditionally this task has been performed using the inefficient manual process of ultimate limiting dilution. We have developed a novel clonal dilution technique using the Laser Enabled Analysis and processing (LEAP (TM)) instrument (Cyntellect Inc. San Diego, CA). The LEAP instrument performs automated fluorescence imaging and real time image analysis to identify and measure fluorescence and morphological parameters of cells. The LEAP instrument also features a laser that can be used to manipulate targeted cells. To perform clonal dilution, cells are seeded at a low density (similar to 10 cells/well) into each well of a 384 well plate and viably stained. The LEAP instrument will then image each well and automatically target all of the cells that are present. Then one cell will be chosen to keep (at random or based on a variety of metrics) and the others will be eliminated by laser ablation. We have successfully used this technique to produce single cell clones of HCT 116 cells, a heterogeneous colorectal cancer model, in 84 percent of wells (originally containing 5 +/- 2.1 cells/well). This is a marked improvement over the traditional technique of ultimate limiting dilution which produces a clone in only 33 percent of wells. The ability to efficiently produce clonal colonies has great utility in the isolation of subpopulations of cancer cells and purification of transformed cell lines.

关键词： LEAP limiting dilution clonal generation photoablative dilution scanning cytometry

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Omnidirectional Morphology Applied to Wood Defects Testing by using Computed Tomography

Omnidirectional Morphology Applied to Wood Defects Testing b...

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2008 IEEE/ASME International conference on Advanced Intelligent Mechatronics, Pages 477-948

作者： Dawei Qi Lei Yu College of Science Northeast Forestry University Harbin 150040 China

ISBN: (纸本)9781424424948

Wood non-destructive testing technology is a new and comprehensive subject. An approach of image edge detection based on morphology of omnidirectional and multi-scale structuring element is constructed by weighting method of morphological operation. In recent years wood non-destructive testing has achieved fast development. Computed tomography (CT) scanning technology has been applied to the detection of internal defects in the logs for the purpose of obtaining prior information, which can be used to arrive at better log sawing decision. In addition to the recognition of wood internal defects, computed tomography (CT) technology can be applied to wood non-destructive testing. Mathematical morphology of omnidirectional and multi-scale element is defined to suppress noise and adapt to different edge in the image. The results of simulation in wood image demonstrate that the method performs better not only in edge detection but also in noise-suppression than classical edge detection operator.

关键词： Computed tomography Wood nondestructive testing mathematical morphology Omnidirectional structure Element image processing

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Identification of vegetable diseases using neural network

Identification of vegetable diseases using neural network

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conference on image processing - Algorithms and Systems v

作者： Zhang Jiacaia Tang Jianjun Li, Yao Beijing Normal Univ Coll Informat Sci & Technol No 19 Xinjiekouwai St Beijing 100875 Peoples R China

ISBN: (纸本)9780819466105

vegetables are widely planted all over China, but they often suffer from the some diseases. A method of major technical and economical importance is introduced in this paper, which explores the feasibility of implementing fast and reliable automatic identification of vegetable diseases and their infection grades from color and morphological features of leaves. Firstly, leaves are plucked from clustered plant and pictures of the leaves are taken with a CCD digital color camera. Secondly, color and morphological characteristics are obtained by standard image processing techniques, for examples, Otsu thresholding method segments the region of interest, image opening following closing algorithm removes noise, Principal Components Analysis reduces the dimension of the original features. Then, a recently proposed boosting algorithm AdaBoost.M2 is applied to RBF networks for diseases classification based on the above features, where the kernel function of RBF networks is Gaussian form with argument taking Euclidean distance of the input vector from a center. Our experiment performs on the database collected by Chinese Academy of Agricultural Sciences, and result shows that Boosting RBF Networks classifies the 230 cucumber leaves into 2 different diseases (downy-mildew and angular-leaf-spot), and identifies the infection grades of each disease according to the infection degrees.

关键词： otsu thresholding image segmentation PCA RBF boosting neural network

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Contribution of image analysis to the definition of explosibility of fine particles resulting from waste recycling process - art. no. 66962B

Contribution of image analysis to the definition of explosib...

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conference on Applications of Digital image processing XXX

作者： Gente, v. La Marca, F. Sapienza Univ Roma Dipartimento Ingn Chim Mat Ambiente I-00184 Rome Italy

ISBN: (纸本)9780819468444

In waste recycling processes, the development of comminution technologies is one of the main actions to improve the quality of recycled products. This involves a rise in fine particles production, which could have some effects on explosibility properties of materials. This paper reports the results of experiments done to examine the explosibility of the fine particles resulting from waste recycling process. Tests have been conducted for the products derived from milling processes operated in different operative conditions. In particular, the comminution tests have been executed varying the milling temperature by refrigerant agents. The materials utilized in explosibility tests were different typologies of plastics coming from waste products (PET, ABS and PP), characterized by size lower than 1 mm. The results of explosibility tests, carried out by mean of a Hartmann Apparatus, have been compared with the data derived from image analysis procedure aimed to measure the morphological characteristics of particles. For each typology of material, the propensity to explode appears to be correlated not only to particle size, but also to morphological properties, linked to the operative condition of the milling process.

关键词： cryogenic comminution explosibility image analysis waste recycling

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A new segmentation method using watersheds on grey level images

A new segmentation method using watersheds on grey level ima...

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International conference on Advanced Computing and Communications

作者： Rao, A. Nagaraja Kumar, v. vijay Nagaraju, C. Univ Mysore MGNIRSA Hyderabad Andhra Pradesh India RGM Coll Engg Tech Nadyal Andhra Pradesh India

ISBN: (纸本)9781424407156

Segmentation is one of the most challenging tasks in image processing as it requires to some extent a semantic understanding of the image. The morphological segmentation paradigm, based on the watershed transform and markers has been extremely successful, both for interactive as for automatic segmentation. Though many algorithms were proposed for watersheds in the literature, but most of them are based on binary images, for finding water catchments basins. In the present study a new method of finding watersheds on grey level image is proposed on 5 X 5 and 3 X 3 masks. To count the number of watersheds on grey levels, a new scheme is proposed for selecting the height of the peak points from where water starts failing, to the central point. The algorithm is applied on human images and textures and a good segmentation is resulted. The present study compares the proposed segmentation scheme with number of watersheds taken into account on different mask sizes.

关键词： watershed binary image grey level image peak points catchments

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Segmentation of kidney using C-v model and anatomy priors

Segmentation of kidney using C-V model and anatomy priors

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conference on Medical Imaging, Parallel processing of images, and Optimization Techniques

作者： Lu, Jinghua Chen, Jie Zhang, Juan Yang, Wenjia Beijing Inst Technol Pattern Recognit & Intelligent Syst Inst Beijing 100081 Peoples R China

ISBN: (纸本)9780819469533

This paper presents an approach for kidney segmentation on abdominal CT images as the first step of a virtual reality surgery system. Segmentation for medical images is often challenging because of the objects' complicated anatomical structures, various gray levels, and unclear edges. A coarse to fine approach has been applied in the kidney segmentation using Chan-vese model (C-v model) and anatomy prior knowledge. In pre-processing stage, the candidate kidney regions are located. Then C-v model formulated by level set method is applied in these smaller ROI, which can reduce the calculation complexity to a certain extent. At last, after some mathematical morphology procedures, the specified kidney structures have been extracted interactively with prior knowledge. The satisfying results on abdominal CT series show that the proposed approach keeps all the advantages of C-v model and overcome its disadvantages.

关键词： medical image segmentation deformable model C-v model level set method anatomy priors ROI extraction kidney CT math morphological operation interactive approach

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