J.-O. Lachaud and A. Montanvert. Deformable meshes with automated topology changes for coarse-to-fine 3D surface extraction. Medical Image Analysis, 3(2):187-- 207, 1999.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....in [23] a triangular decomposition of the rectangular image grid has been performed. With every iteration, the intersections of the contours with the triangular grids are computed that is followed by a decision rule for connecting the intersections among themselves for merging splitting. In [25] the self intersections are detected based on the distance between the vertices of the evolving deformable surfaces. 26] also depends on detection of merging splitting and subsequently applying topological operators to perform actual topological changes. On the contrary, although we are ....

J.-O. Lachaud and A. Montanve rt, "Deformable meshes with automated topology changes for coarse-to-fine three-dimensional surface extraction," Medical Image Analysis, vol. 3(2), pp.187-207, 1999.

....a deformable contour with a set of growing seeds. For parametric contours, it is in general not possible to achieve any automatic topological changes. How ever, several algorithms have been proposed to overcome this limitation [Leitner and Cinquin, 1991, McInerney and Terzopoulos, 1995, Lachaud and Montanvert, 1999] These approaches are discussed later in this paper. Sometimes, it is necessary to handle open active contours for proper image segmentation as shown with the work of Berger et al. Berger and Mohr, 1990] Open contours are even more widely used when considering the more general problem of ....

....Figure 9: Segmentation of a curvy shape using (a) Laplacian smoothing and (b) curvature diffusive internal force expressions. 23 Figure 10: Topological operator applied to two edges of the same connected component (left) or two different connected components (right) and Lachaud and Montanvert [Lachaud and Montanvert, 1999]. Using Mc Inerney et a .approach, all topological changes occur by computing the contour intersections with a simplicial decomposi tion of space. The contour is reparameterized at each iteration, the intersections with the simplicial domain being used as the new vertices. Recently Lachaud et al. ....

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Lachaud, J.-O. and Montanvert, A. (1999). Deformable meshes with automated topology changes for coarse-to-fine three-dimensional surface extraction. Medical Image Analysis, 3(2):187-207.

....of abstraction into the typical deformable model framework of energy minimization. Consequently, these models remain sensitive to initial conditions and spurious image features in image interpretation tasks. Various hierarchical versions of boundary based deformable models have been developed [10,12,8,7] but again fail to provide a natural global description of an object the multi scale deformation control is constructed upon arbitrary boundary point sets and not upon objectrelative geometry. Several global or olume based shape representation or deformation mechanisms do exist [1,14,15,17] ....

J.O. Lachaud and A. Montanvert, "Deformable meshes with automated topology changes for coarse-to-fine threedimensional surface extraction", Medical Image Analysis, Vol. 3, No. 1, 1999, pp. 1-21.

....class of deformable models, so called the level sets or geodesic active contours surfaces # . The application of level sets in medical segmentation of medical imagery became extremely popular because of its ability to capture the topology of shapes in medical imagery. Recently, Lachaud (see [4], 5] 6] showed a relationship between topology and isosurface extraction. Malgouyres et al. 7] also recently published an excellent paper on topology preservation within digital surfaces. A detailed survey on digital topology in CVGIP # canbeseenbyKonget al... 8] and also the related ....

Lachaud, J., O. and Montanvert, A., Deformable Meshes with Automated Topology Changes for Coarse-to-Fine 3D Surface Extraction, Medical Image Analysis, Vol. 3, No. 2, pp. 187207, 1999.

....may still require extensive user interaction. Interestingly, in contrast to the 2D case, there are several 3D parametric deformable surface models that are capable of automatically adapting to object topology (Leitner and Cinquin 1991; Szeliski et al. 1993; Whitaker 1994; Malladi et al. 1996; Lachaud and Montanvert 1999). Unlike T surfaces which are automatically reparameterized via the ACID framework, the reparameterization process of these 4 models is typically based on subdivision rules and not on the intrinsic local geometry of the target object; these triangle refinement mechanisms can create initial ....

Lachaud, J.-O. and Montanvert, A. (1999). Deformable Meshes with Automated Topology Changes for Coarse-to-fine 3D Surface Extraction. Medical Image Analysis 3(2):187--207.

....this technique is not effective. Three dimensional deformable surfaces or balloons , on the other hand, are potentially faster, make more effective use of the 3D data, and, in many situations, require less user input and guidance. Several variants have been developed [12] 13] 14] 15] 16] [17]. In this paper, we present a natural extension of our ACID framework that is suitable for deformable surfaces. In particular, we develop topology adaptive deformable surfaces, dubbed T surfaces [18] for use on volume images. After a brief review of the planar, T snakes formulation in the next ....

....through intuitive interaction mechanisms. Several researchers have attempted to overcome the limitations of parametric deformable surface models by adding greater functionality or by using discrete deformable meshes with automatic model refinement and topology adaptation mechanisms [12] 14] [17], 35] 36] Like T surfaces, these models can support user interaction IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. XX, NO. Y, MONTH 1999 109 (a) b) c) d) e) f) g) Fig. 10. T surface segmentation of ventricles from MR image volume of the brain. through energy force based constraints. ....

J.-O. Lachaud and A. Montanvert, "Deformable Meshes with Automated Topology Changes for Coarse-to-fine 3D Surface Extraction, " Medical Image Analysis, vol. 3, no. 2, pp. 187--207, 1999.

....contours. This is because the update of an implicit contour requires the update of at least a narrow band around each contour. On the other hand, parametric contours cannot in general achieve any automatic topological changes, also several algorithms have been proposed to overcome this limitation [11, 14, 10]. This paper includes three distinct contributions corresponding to three different modeling levels of parametric active contours: 1. Discretization. We propose two algorithms for controlling the relative vertex spacing and the total number of vertices. On one hand, the vertex spacing is ....

....explicit integration scheme is linked to the choice of ff i . We have found experimentally, without having a formal proof yet, that we obtain a stable iterative scheme if we choose ff i 0:5. 5 Topology constraints Automatic topology changes of parametric contour has been previously proposed in [11, 14, 10]. In McInerney et al. approach, all topological changes occur by computing the contour intersections with a simplicial decomposition of space. The contour is reparameterized at each iteration, the intersections with the simplicial domain being used as the new vertices. Recently Lachaud et al. [10] ....

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J.-O. Lachaud and A. Montanvert. Deformable meshes with automated topology changes for coarse-to-ne three-dimensional surface extraction. Medical Image Analysis, 3(2):187207, 1999.

....determine the appropriate global topology for the initial mesh [40, 43, 28, 38] The largest advantage of our algorithm is our ability to extract a surface of arbitrary topology without any input from the user. Solvers which accommodate topological modifications are possible, but rather delicate [31, 39]. Instead we opt for a robust algorithm which automatically extracts a surface with the correct global topology from the volume data without recourse to MC. Topological Graphs can be constructed to encode the topology of a surface. Our algorithm uses the adjacency relationships of the voxels in ....

LACHAUD, J.-O., AND MONTANVERT, A. Deformable Meshes with Automated Topology Changes for Coarseto -fine 3D Surface Extraction. Medical Image Analysis 3, 2 (1999), 187--207.

....by merging dioeerent intersecting contours, it is possible to initialize a deformable contour with a set of growing seeds. For parametric contours, it is in general not possible to achieve any automatic topological changes. However, several algorithms have been proposed to overcome this limitation [18, 21, 17]. These approaches are discussed later in this paper. Sometimes, it is necessary to handle open active contours for proper image segmentation as shown with the work of Berger et al. 2] Open contours are even more widely used when considering the more general problem of regularization and ....

.... to two edges of the same connected component (left) or two dioeerent connected components (right) 4 Topology Constraints Automatic topology changes of parametric contours have been previously proposed by Leitner and Cinquin [18] Mc Inerney and Terzopoulos [21] and Lachaud and Montanvert [17]. Using Mc Inerney et al..approach, all topological changes occur by computing the contour intersections with a simplicial decomposition of space. The contour is reparameterized at each iteration, the intersections with the simplicial domain being used as the new vertices. Recently Lachaud et al. ....

[Article contains additional citation context not shown here]

J.-O. Lachaud and A. Montanvert. Deformable meshes with automated topology changes for coarse-to-ne three-dimensional surface extraction. Medical Image Analysis, 3(2):187207, 1999.

....a similar method that use a simplicial regular subdivision of the space to detect and solve topological problems. This algorithm is less ecient than Delingette s (O(n ) per iteration instead of O(n) but has the advantage of being easy to extend to the three dimensional case. The authors of [6] propose a di erent approach based on distance constraints on the edges of the deformable model. Although they formulate it for the three dimensional case, the principle is valid for the bi dimensional case too. With an appropriate data structure the time complexity of this algorithm is reduced to ....

....ne resolution is thus achieved in the interesting parts of the image while a coarse one is kept elsewhere. With this technique, the complexity of the model is made signi cantly more independent of the image resolution. More precisely, the model we propose is an extension of the one presented in [6]. In this model, the topological consistency is maintained using distances estimations. However, to work properly, the model needs to have a regular density. To achieve adaptative resolution, our idea is to change the Euclidean metric with a locally deformed metric that geometrically expands the ....

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J.-O. Lachaud and A. Montanvert. Deformable meshes with automated topology changes for coarse-to- ne 3D surface extraction. Medical Image Analysis, 3(2):187{ 207, 1999.

.... This method is not so ecient as the one proposed by Delingette (O(n ) per iteration instead of O(n) but the properties of the simplicial grid makes it possible to extend the model to 3D image segmentation [13] which seems not to be so obvious with the former) Finally Lachaud and Montanvert [9] propose a di erent method for 3D image segmentation. The detection of the collision is based on simple distance constraints between the model vertices: the rst constraint ensures that the mesh keeps a regular sampling, the second constraint implies that the distances between non neighbor vertices ....

.... This point of view has a signi cant advantage over the rst formulation: new forces can now be introduced to speed up the convergence of the model or to improve the segmentation (for examples see [4] and [20] Moreover, such a mechanical system is easy to extend to three dimensional spaces [6, 9]. To determine the displacement of each particle at a given step, many authors directly apply Newton s laws of motion and then solve the resulting di erential equations (e.g. 20, 4, 7] However, we propose to use the Lagrangian approach to express the dynamics of each particle, since it can be ....

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J.-O. Lachaud and A. Montanvert. Deformable meshes with automated topology changes for coarse-to- ne 3D surface extraction. Medical Image Analysis, 3(2):187{ 207, 1999.

....to simple objects. Furthermore the snake cannot dynamically change its topology according to its geometric deformation. To overcome this issue, several works propose automated topology adaptation techniques. Some are based on global remeshing [15, 16, 4] others performs local recon gurations [10, 3, 8]. However, if some of these works are still valid for 3D images, they are mostly ad hoc and dicult to extend to arbitrary dimensions. An other approach consist in formulating the problem in term of front propagation instead of minimizing an energy [18, 14, 1] This formulation avoids the ....

J.-O. Lachaud and A. Montanvert. Deformable meshes with automated topology changes for coarse-to- ne 3D surface extraction. Medical Image Analysis, 3(2):187{ 207, 1999.

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J.-O. Lachaud and A. Montanvert. Deformable meshes with automated topology changes for coarse-to-fine 3D surface extraction. Medical Image Analysis, 3(2):187-- 207, 1999.

No context found.

J.-O. Lachaud and A. Montanvert. Deformable meshes with automated topology changes for coarse-to-fine three-dimensional surface extraction. Medical Image Analysis, 3(2):187 -- 207, 1998.

No context found.

J.-O. Lachaud and A. Montanvert. Deformable meshes with automated topology changes for coarse-to-fine three-dimensional surface extraction. Medical Image Analysis, 3(2):187 -- 207, 1998.

No context found.

J.-O. Lachaud and A. Montanvert, "Deformable meshes with automated topology changes for coarse-to-fine three-dimensional surface extraction, " Med. Image Anal., vol. 3, no. 2, pp. 187--207, 1999.

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J.-O. Lachaud and A. Montanvert. Deformable meshes with automated topology changes for coarse-to-fine three-dimensional surface extraction. Medical Image Analysis, 3(2), 1998.

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