Topology preservation is a crucial issue of digital topology. Various applications of binary imageprocessing rest on topology preserving operators. Earlier studies in this topic mainly concerned with reductions (i.e....
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Topology preservation is a crucial issue of digital topology. Various applications of binary imageprocessing rest on topology preserving operators. Earlier studies in this topic mainly concerned with reductions (i.e., operators that only delete some object points from binary images), as they form the basis for thinning algorithms. However, additions (i.e., operators that never change object points) also play important role for the purpose of generating discrete Voronoi diagrams or skeletons by influence zones (SKIZ). Furthermore, the use of general operators that may both add and delete some points to and from objects in pictures are suitable for contour smoothing. Therefore, in this paper we present some new sufficient conditions for topology preserving reductions, additions, and general operators. Two additions for 2D and 3D contour smoothing are also reported.
Thinning is a frequently applied technique for producing skeletons from digital binary pictures in a topology-preserving way. Bertrand proposed a two-step thinning scheme that is based on P-simple points. In this pape...
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The problem of reconstruction of binary matrices from their fan-beam projections is studied. A fan-beam projection model is implemented and used in systematic experiments in order to determine the optimal parameter va...
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The problem of reconstruction of binary matrices from their fan-beam projections is studied. A fan-beam projection model is implemented and used in systematic experiments in order to determine the optimal parameter values for data acquisition and reconstruction algorithm. The fan-beam model, the reconstruction algorithm, the simulation experiments, and the results are discussed in the paper.
Skeletons are region based shape descriptors that play important role in shape representation. This paper introduces a novel sequential thinning approach for n-dimensional binary objects (n = 1, 2, 3). Its main streng...
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ISBN:
(纸本)9780889868946
Skeletons are region based shape descriptors that play important role in shape representation. This paper introduces a novel sequential thinning approach for n-dimensional binary objects (n = 1, 2, 3). Its main strength lies in its order-independency, i.e., it can produce the same skeletons for any visiting orders of border points. Furthermore, this is the first scheme in this field that is also applicable for higher dimensions.
Thinning as a layer-by-layer reduction is a frequently used technique for skeletonization. Sequential thinning algorithms usually suffer from the drawback of being order-dependent, i.e., their results depend on the vi...
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ISBN:
(纸本)9780889869219
Thinning as a layer-by-layer reduction is a frequently used technique for skeletonization. Sequential thinning algorithms usually suffer from the drawback of being order-dependent, i.e., their results depend on the visiting order of object points. Earlier order-independent sequential methods are based on the conventional thinning schemes that preserve endpoints to provide relevant geometric information of objects. These algorithms can generate centerlines in 2D and medial surfaces in 3D. This paper presents an alternative strategy for order-independent thinning which follows an approach, proposed by Bertrand and Couprie, which accumulates so-called isthmus points. The main advantage of this order-independent strategy over the earlier ones is that it makes also possible to produce centerlines of 3D objects.
Thinning is a frequently applied technique for extracting skeletons or medial surfaces from volumetric binary objects. It is an iterative object reduction: border points that satisfy certain topological and geometric ...
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Reductions transform binary pictures only by changing some black points to white ones. Parallel reductions can alter a set of black points simultaneously, while a sequential reduction traverses the black points of a p...
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Usage of computer-readable visual codes is common in everyday life. The reading process of visual codes consists of two steps, localization and data decoding. This paper introduces a fast and robust method for localiz...
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ISBN:
(纸本)9789897580901
Usage of computer-readable visual codes is common in everyday life. The reading process of visual codes consists of two steps, localization and data decoding. This paper introduces a fast and robust method for localization of visual codes using Fuzzy Inference Systems based on simplistic, attentive features which can be optionally extended with cell histograms. Input image properties, assigned membership functions and efficiency of the system has been evaluated and discussed, showing FIS is a viable alternative for rapid QR code recognition in the image domain. The basic approach can be also used with lookup tables, that speeds up image cell evaluation and makes it ideal for embedded systems.
This paper presents a new kind of uniform spline curve, named trigonometric polynomial B-splines, over space Ω = span{sini,cost, tk-3,tk-4, …,t, 1} of which k is an arbitrary integer larger than or equal to 3. We sh...
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This paper presents a new kind of uniform spline curve, named trigonometric polynomial B-splines, over space Ω = span{sini,cost, tk-3,tk-4, …,t, 1} of which k is an arbitrary integer larger than or equal to 3. We show that trigonometric polynomial B-spline curves have many similar properties to traditional B-splines. Based on the explicit representation of the curve we have also presented the subdivision formulae for this new kind of curve. Since the new spline can include both polynomial curves and trigonometric curves as special cases without rational form, it can be used as an efficient new model for geometric design in the fields of CAD/CAM.
The need for courses on medical graphics, especially in real-time volume graphics, has increased. In order for students to develop skills sufficient to work on independent studies, or Bachelor's or Master's Th...
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ISBN:
(纸本)9781450318303
The need for courses on medical graphics, especially in real-time volume graphics, has increased. In order for students to develop skills sufficient to work on independent studies, or Bachelor's or Master's Theses, they will need 3 courses on computergraphics: course I teaches basic computergraphics according to the rendering pipeline;course II extends into advanced rendering and modeling algorithms and lays the foundation for computer-generated visualization;course III can then use these foundations to extend into medical graphics.
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