27,260 results for ResearchSpace@Auckland

  • Life-and-Death Problem Solver in Go

    Lee, Byung-Doo (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). The life-and-death problem in Go is a basic and essential problem to be overcome in implementing a computer Go program. This paper proposes a new heuristic searching model which can reduce the branching factor in a game tree. For constructing the first level of a game tree, we implement pattern clustering and eye shape analysis to get the set of the first moves, thereby reducing the branching factor of the game tree. The empirical result for game tree searching with these methods is promising. We also suggest several problems to address for making game tree searching more robust, such as: coping with situations where the number of legal moves in the surrounded group is more than 8, creating an accurate heuristic evaluation function, and dealing with ko fighting.

    View record details
  • A Revision of a 3D Skeletonization Algorithm

    Pan, Mian; Klette, Gisela (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). This report is about a project that started with studying and testing an existing program by K.Palagyi et al. published in [4]. It provides several combinations of preprocessing steps with the traditional thinning approach. This study lead to a proposal of a new characterization of non-simple voxels, which has been implemented and proved to be e±cient for reducing the running time of the algorithm. Altogether, we suggest a revision of the test of voxels to be simple in the discussed 3D skeletonization algorithm.

    View record details
  • Digital Planarity - A Review

    Brimkov, Valentin; Coeurjolly, David (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). Digital planarity is defined by digitizing Euclidean planes in the three-dimensional digital space of voxels; voxels are given either in the grid point or the grid cube model. The paper summarizes results (also including most of the proofs) about different aspects of digital planarity, such as self-similarity, supporting or separating Euclidean planes, characterizations in arithmetic geometry, periodicity, connectivity, and algorithmic solutions. The paper provides a uniform presentation, which further extends and details a recent book chapter in (Klette and Rosenfeld 2004). [This report has been updated in April 2006, at the end of the reviewing process of its journal publication. Results stated are still as in the original 2004 report, but the report was improved at several places due to reviewers comments.]

    View record details
  • Multi-Sensor Panorama Fusion and Visualization

    Scheibe, Karsten; Scheele, Martin (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). The paper describes a general approach for scanning and visualizing panoramic (360) indoor scenes. It combines range data acquired by a laser range finder with color pictures acquired by a rotating CCD line camera. The paper describes coordinate systems of both sensors, specifies the fusion of range and color data acquired by both sensors, and reports on three dierent alternatives for visualizing the generated 3D data set. Compared to earlier publications the recent approach also utilizes an improved method for calculating the spatial (geometric) correspondence between laser diode of the laser range finder and the focal point of the rotating CCD line camera. Calibration is not a subject in this paper; we assume that calibrated parameters are available utilizing a method as described in [12].

    View record details
  • Surface Area and Capacity of Ellipsoids in n Dimensions. (CITR)

    Tee, Garry (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). The surface area of a general n-dimensional ellipsoid is represented as an Abelian integral, which can readily be evaluated numerically. If there are only 2 values for the semi-axes then the area is expressed as an elliptic integral, which reduces in most cases to elementary functions. The capacity of a general n-dimensional ellipsoid is represented as a hyperelliptic integral, which can readily be evaluated numerically. If no more than 2 lengths of semi-axes occur with odd multiplicity, then the capacity is expressed in terms of elementary functions. If only 3 or 4 lengths of semi-axes occur with odd multiplicity, then the capacity is expressed as an elliptic integral.

    View record details
  • Lovasz theta-function of a class of graphs representing digital lines

    Brimkov, Valentin; Barneva, Reneta (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). We consider the problem of estimating the Shannon capacity of a circulant graph C_nj of degree four with n vertices and chord length j, , by computing its Lovasz theta function theta(C_nj ). Our interest in this problem is driven by possible applications to error-free communication of data describing the structure of a digital line. The latter can be represented in terms of spyrographs [12], which, as a matter of fact, are circulants of degree four. We present an algorithm for theta(C_nj ) computation that takes O(j) operations if j is an odd number, and O(n/j) operations if j is even. On the considered class of graphs our algorithm strongly outperforms the known algorithms for theta function computation.

    View record details
  • Pose Estimation of Free-form Objects (Theory and Experiments)

    Rosenhahn, Bodo; Sommer, Gerald (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). In this report we present geometric foundations and an algorithmic approach to deal with the 2D-3D pose estimation problem for free-form surface models. This work is an extension to our former works presented in [28]. But whereas in [28] 1D contour models are treated, here the extension to 2D free-form surface models is presented. Similar to our former works we use a parametric representation of surfaces and apply Fourier transformations to gain low-pass descriptions of the object. We present an algorithm for pose estimation, which uses the silhouette of the object as image information and recovers the 3D pose of the object even for changing aspects of the object during image sequences. We further present extensions to couple surface and contour information on objects and show the potential of our chosen approach even for complex objects and scenes.

    View record details
  • The application of TD(?) Learning to the Opening Games of 19x19 Go

    Lee, Byung-Doo; Guesgen, Hans (2003)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). This paper describes the results of applying Temporal Difference (TD) learning with a network to the opening game problems in Go. The main difference from other research is that this experiment applied TD learning to the fullsized (19x19) game of Go instead of a simple version (e.g., 9x9 game). We discuss and compare TD(?) learning for predicting an opening game's winning and for finding the best game among the prototypical professional opening games. We also tested the performance of TD(?)s by playing against each other and against the commercial Go programs. The empirical result for picking the best game is promising, but there is no guarantee that TD(?) will always pick the identical opening game independent of different values. The competition between two TD(?)s shows that TD(?) with a higher ? has better performance.

    View record details
  • Digital hyperplane recognition in arbitrary fixed dimension

    Brimkov, Valentin; Dantchev, Stefan (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). We consider the following problem. Given a set of points M = {p1, p2, . . . , pm} ? Rn, decide whether M is a portion of a digital hyperplane and, if so, determine its analytical formulation. In our setting p1, p2, . . . , pm may be arbitrary points (possibly, with rational and/or irrational coefficients) and the dimension n may be any arbitrary fixed integer. We provide an algorithm that solves the problem with O(mlogD) arithmetic operations, where D is a bound on the value of the digital plane coefficients. The solution is based on reducing the digital hyperplane recognition problem to an integer linear programming problem of fixed dimension within an algebraic model of computation.

    View record details
  • Footprint Identification of Weta and Other Insects

    Deng, Lea; Bertinshaw, Daniel; Klette, Gisela; Jeffries, Darryl (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). Using tracking tunnels or tracking cards to obtain the footprints of active animals living in a specific area is useful for biosecurity research as well as environment monitoring. In the absence of human experts, a feasible computer classifier could be constructed to identify species of insects from their footprints. The essential step to develop this classifier is to obtain representative attributes on which we can perform analysis using image processing technology, geometry, etc. This paper presents procedures for an approach to build up such a classifier by discussing three different attribute heuristics.

    View record details
  • The Class of Simple Cube-Curves Whose MLPs Cannot Have Vertices at Grid Points

    Li, Fajie; Klette, Reinhard (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). We consider simple cube-curves in the orthogonal 3D grid of cells. The union of all cells contained in such a curve (also called the tube of this curve) is a polyhedrally bounded set. The curve's length is defined to be that of the minimum-length polygonal curve (MLP) fully contained and complete in the tube of the curve. So far only one general algorithm called rubber-band algorithm was known for the approximative calculation of such a MLP. There is an open problem which is related to the design of algorithms for calculation a 3D MLP of a cube-curve: Is there a simple cube-curve such that none of the vertices of its 3D MLP is a grid vertex? This paper constructs an example of such a simple cube-curve. We also characterize this class of cube-curves.

    View record details
  • Analytical Honeycomb Geometry for Raster and Volume Graphics

    Brimkov, Valentin; Barneva, Reneta (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). In this paper we investigate the advantages of using hexagonal grids in raster and volume graphics. In 2D, we present a hexagonal graphical model based on a hexagonal grid. In 3D, we introduce two honeycomb graphical models in which the voxels are hexagonal prisms, and we show that these are the only possible models under certain reasonable conditions. In the framework of the proposed models, we design two- and three-dimensional analytical honeycomb geometry of linear objects, as well as of circles and spheres. We demonstrate certain advantages of the honeycomb models and address algorithmic and complexity issues.

    View record details
  • Corner Detection and Curve Partitioning Using Arc-Chord Distance

    Marji, Majed; Klette, Reinhard (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). Several authors have proposed algorithms for curve partitioning using the arc-chord distance formulation, where a chord whose associated arc spans k pixels is moved along the curve and the distance from each border pixel to the chord is computed. The scale of the corners detected by these algorithms depends on the choice of integer k. Without a priori knowledge about the curve, it is difficult to choose a k that yields good results. This paper presents a modified method of this type that can tolerate the effects of an improper choice of k to an acceptable degree. The new algorithm seems to yield generally good results.

    View record details
  • Footprint Recognition of Rodents and Insects

    Hasler, Nils; Klette, Reinhard; Agnew, Warren (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). In today s pest control operations large numbers of tracking tunnels are used to estimate the number of rodents present in the target area, providing a basis for planning the required amount of poison. The marks left in the tunnels have to be interpreted by trained experts. This article introduces two methods that make a step towards automating the process of recognizing footprints of rodents and insects. Furthermore two classification methods (Principal Component Analysis, a simple Na¨?ve Bayes classifier) are studied to distinguish the four examined insect species. Here, a combination of both classifiers proved superior to using just one method.

    View record details
  • Performance Evaluation of Binarizations of Scanned Insect Footprints

    Woo, Young Woon (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). The paper compares six conventional binarization methods for the special purpose of subsequent analysis of scanned insect footprints. We introduce a new performance criterion for performance evaluation. The six different binarization methods are selected from different methodologically categories, and the proposed performance criterion is related to the specific characteristics of insect footprints of having a very small percentage of object areas. The results indicate that a higher-order entropy binarization algorithm, such as proposed by Abutaleb, offers best results for further pattern recognition application steps for the analysis of scanned insect footprints.

    View record details
  • Minimum-Length Polygon of a Simple Cube-Curve in 3D Space

    Li, Fajie; Klette, Reinhard (2004)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). We consider simple cube-curves in the orthogonal 3D grid of cells. The union of all cells contained in such a curve (also called the tube of this curve) is a polyhedrally bounded set. The curve's length is defined to be that of the minimum-length polygonal curve (MLP) fully contained and complete in the tube of the curve. So far, only a"rubber-band algorithm" is known to compute such a curve approximately. We provide an alternative iterative algorithm for the approximative calculation of the MLP for curves contained in a special class of simple cube-curves (for which we prove the correctness of our alternative algorithm), and the obtained results coincide with those calculated by the rubber-band algorithm.

    View record details
  • Global Curvature Estimation for Corner Detection

    Hermann, Simon; Klette, Reinhard (2005)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). The paper starts with presenting three curvature estimators which follow definitions (approaches) in differential geometry. Digital-straight segment (DSS) approximation is used in those estimators, we point to problems caused by this approach, and propose simple ways for eliminating those problems. The paper then informs about multigrid analysis experiments, where all estimators appear to be multigrid convergent when digitizing an ellipse. The paper also applies these estimators for corner detection and compares their performance with a recently published heuristic corner-detection approach by means of multigrid analysis. Experiments indicate that corner detectors (based on curvature estimation) perform about as good as the heuristic method for large grid resolutions, and one detector might be even superior.

    View record details
  • Volume Measurement Using a Laser Scanner

    Zhang, Xin; Morris, John (2005)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). This article discusses ways of measuring accuracy of a laser range finder (LRF) using a specially designed calibration cube (with 3D calibration marks) in the context of a particular application (i.e., measuring volumes). We also compare (by means of experiments) two alternative volume estimation methods.

    View record details
  • Structure from Motion in the Presence of Noise

    Liu, Gang; Klette, Reinhard (2005)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). Structure from Motion (SfM) is one of the most attractive approaches within computer vision which aims on estimating 3D structure from 2D image sequences. This paper focuses on a stability analysis and studies the error propagation of image noise. To stabilize SfM, we further present two optimization schemes by using a priori knowledge of the scene.

    View record details
  • Understanding Tracks of Different Species of Rats (2005)

    Yuan, Guannan; Russell, James; Rosenhahn, Bodo; Stones-Havas, Steven (2005)

    Report
    The University of Auckland Library

    You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s). Recognition of animal tracks plays an important role in environmental research and pest control. So far such track analysis can only be accurately carried out by experienced biologists. In this paper we discuss the potential of image analysis methodologies for allowing automatic identification of rat tracks. The approach is basically a refinement of template matching (as designed earlier for automated track localization), now also allowing identification of rat species.

    View record details