Fast connected component labeling algorithm: a non voxel-based approach

This paper presents a new approach to achieve connected component labeling on both binary images and volumes by using the Extreme Vertices Model (EVM), a representation model for orthogonal polyhedra, applied to digital images and volume datasets recently. In contrast with previous techniques, this method does not use a voxel-based approach but deals with the inner sections of the object.Postprint (published version

Impact of adjunct cytogenetic abnormalities for prognostic stratification in patients with myelodysplastic syndrome and deletion 5q.

This cooperative study assessed prognostic factors for overall survival (OS) and risk of transformation to acute myeloid leukemia (AML) in 541 patients with de novo myelodysplastic syndrome (MDS) and deletion 5q. Additional chromosomal abnormalities were strongly related to different patients' characteristics. In multivariate analysis, the most important predictors of both OS and AML transformation risk were number of chromosomal abnormalities (P<0.001 for both outcomes), platelet count (P<0.001 and P=0.001, respectively) and proportion of bone marrow blasts (P<0.001 and P=0.016, respectively). The number of chromosomal abnormalities defined three risk categories for AML transformation (del(5q), del(5q)+1 and del(5q)+ ≥ 2 abnormalities) and two for OS (one group: del(5q) and del(5q)+1; and del(5q)+ ≥ 2 abnormalities, as the other one); with a median survival time of 58.0 and 6.8 months, respectively. Platelet count (P=0.001) and age (P=0.034) predicted OS in patients with '5q-syndrome'. This study demonstrates the importance of additional chromosomal abnormalities in MDS patients with deletion 5q, challenges the current '5q-syndrome' definition and constitutes a useful reference series to properly analyze the results of clinical trials in these patients

The Extreme Vertices Model (EVM) for orthogonal polyhedra

Orthogonal Polyhedra offer a worthy-to-explore simplification. In this work we propose a specific model for representing orthogonal polyhedra that allows simple and robust algorithms for performing the most usual and demanding tasks, such as closed and regularized boolean operations; solid splitting and other set membership classification operations; and so on. These algorithms have much lower complexities than their counterparts for general objects have, and they also avoid floating-point computations.Postprint (published version

The Extreme Vertices Model (EVM) for orthogonal polyhedra

Orthogonal Polyhedra offer a worthy-to-explore simplification. In this work we propose a specific model for representing orthogonal polyhedra that allows simple and robust algorithms for performing the most usual and demanding tasks, such as closed and regularized boolean operations; solid splitting and other set membership classification operations; and so on. These algorithms have much lower complexities than their counterparts for general objects have, and they also avoid floating-point computations

Converting orthogonal polyhedra from extreme vertices model to B-Rep and to alternating sum of volumes

In recent published papers we presented the Extreme Vertices Model (EVM), a concise and complete model for representing orthogonal polyhedra and pseudo-polyhedra (OPP). This model exploits the simplicity of its domain by allowing robust and simple algorithms for set-membership classification and Boolean operations that do not need to perform floating-point operations. Several applications of this model have also been published, including the suitability of OPP as geometric bounds in Constructive Solid Geometry (CSG). In this paper, we present an algorithm which converts from this model into a B-Rep model. We also develop the application of the Alternating Sum of Volumes decomposition to this particular type of polyhedra by taking advantage of the simplicity of the EVM. Finally we outline our future work, which deals with the suitability of the EVM in the field of digital images processing.Postprint (published version

Orthogonal polyhedra as geometric bounds in constructive solid geometry

Set membership classification and, specifically, the evaluation of a CSG tree are problems of a certain complexity. Several techniques to speed up these processes have been proposed such as Active Zones, Geometric Bounds and the Extended Convex Differences Tree. Boxes are the most common geometric bounds studied but other bounds such as spheres, convex hulls and prisms have also been proposed. In this work we propose orthogonal polyhedra as geometric bounds in the CSG model. CSG primitives are approximated by orthogonal polyhedra and the orthogonal bound of the object is obtained by applying the corresponding boolean algebra. A specific model for orthogonal polyhedra is presented that allows a simple and robust boolean operations algorithm between orthogonal polyhedra. This algorithm has linear complexity (is based on a merging process) and avoids floating-point computation.Postprint (published version

Converting orthogonal polyhedra from extreme vertices model to B-Rep and to alternating sum of volumes

In recent published papers we presented the Extreme Vertices Model (EVM), a concise and complete model for representing orthogonal polyhedra and pseudo-polyhedra (OPP). This model exploits the simplicity of its domain by allowing robust and simple algorithms for set-membership classification and Boolean operations that do not need to perform floating-point operations. Several applications of this model have also been published, including the suitability of OPP as geometric bounds in Constructive Solid Geometry (CSG). In this paper, we present an algorithm which converts from this model into a B-Rep model. We also develop the application of the Alternating Sum of Volumes decomposition to this particular type of polyhedra by taking advantage of the simplicity of the EVM. Finally we outline our future work, which deals with the suitability of the EVM in the field of digital images processing

Orthogonal polyhedra as geometric bounds in constructive solid geometry

Set membership classification and, specifically, the evaluation of a CSG tree are problems of a certain complexity. Several techniques to speed up these processes have been proposed such as Active Zones, Geometric Bounds and the Extended Convex Differences Tree. Boxes are the most common geometric bounds studied but other bounds such as spheres, convex hulls and prisms have also been proposed. In this work we propose orthogonal polyhedra as geometric bounds in the CSG model. CSG primitives are approximated by orthogonal polyhedra and the orthogonal bound of the object is obtained by applying the corresponding boolean algebra. A specific model for orthogonal polyhedra is presented that allows a simple and robust boolean operations algorithm between orthogonal polyhedra. This algorithm has linear complexity (is based on a merging process) and avoids floating-point computation

Fast connected component labeling algorithm: a non voxel-based approach

This paper presents a new approach to achieve connected component labeling on both binary images and volumes by using the Extreme Vertices Model (EVM), a representation model for orthogonal polyhedra, applied to digital images and volume datasets recently. In contrast with previous techniques, this method does not use a voxel-based approach but deals with the inner sections of the object