Xtru3D: Single-View 3D Object Reconstruction from Color and Depth Data

D object reconstruction from single image has been a noticeable research trend in recent years. The most common method is to rely on symmetries of real-life objects, but these are hard to compute in practice. However, a large class of everyday objects, especially when manufactured, can be generated by extruding a 2D shape through an extrusion axis. This paper proposes to exploit this property to acquire 3D object models using a single RGB+Depth image, such as those provided by available low-cost range cameras. It estimates the hidden parts by exploiting the geometrical properties of everyday objects, and both depth and color information are combined to refine the model of the object of interest. Experimental results on a set of 12 common objects are shown to demonstrate not only the effectiveness and simplicity of our approach, but also its applicability for tasks such as robotic grasping.The research leading to these results has been funded by the HANDLE European project (FP7/2007-2013) under grant agreement ICT 231640-http://www.handle-project.eu.Publicad

The role of habitat features in a primary succession

In order to determine the role of habitat features in a primary succession on lava domes of Terceira Island (Azores) we addressed the following questions: (1) Is the rate of cover development related to environmental stress? (2) Do succession rates differ as a result of habitat differences? One transect, intercepting several habitats types (rocky hummocks, hollows and pits, small and large fissures), was established from the slope to the summit of a 247 yr old dome. Data on floristic composition, vegetation bioarea, structure, demography and soil nutrients were collected. Quantitative and qualitative similarities among habitats were also analyzed. Cover development and species accumulation are mainly dependent on habitat features. Habitat features play a critical role in determining the rate of succession by providing different environmental conditions that enable different rates of colonization and cover development. Since the slope’s surface is composed of hummocks, hollows and pits the low succession rates in these habitats are responsible for the lower rates of succession in this geomorphologic unit, whereas the presence of fissures in the dome’s summit accelerates its succession rate

Peacock Bundles: Bundle Coloring for Graphs with Globality-Locality Trade-off

Bundling of graph edges (node-to-node connections) is a common technique to enhance visibility of overall trends in the edge structure of a large graph layout, and a large variety of bundling algorithms have been proposed. However, with strong bundling, it becomes hard to identify origins and destinations of individual edges. We propose a solution: we optimize edge coloring to differentiate bundled edges. We quantify strength of bundling in a flexible pairwise fashion between edges, and among bundled edges, we quantify how dissimilar their colors should be by dissimilarity of their origins and destinations. We solve the resulting nonlinear optimization, which is also interpretable as a novel dimensionality reduction task. In large graphs the necessary compromise is whether to differentiate colors sharply between locally occurring strongly bundled edges ("local bundles"), or also between the weakly bundled edges occurring globally over the graph ("global bundles"); we allow a user-set global-local tradeoff. We call the technique "peacock bundles". Experiments show the coloring clearly enhances comprehensibility of graph layouts with edge bundling.Comment: Appears in the Proceedings of the 24th International Symposium on Graph Drawing and Network Visualization (GD 2016

Skeletons for Distributed Topological Computation

Parallel implementation of topological algorithms is highly desirable, but the challenges, from reconstructing algorithms around independent threads through to runtime load balancing, have proven to be formidable. This problem, made all the more acute by the diversity of hardware platforms, has led to new kinds of implementation platform for computational science, with sophisticated runtime systems managing and coordinating large threadcounts to keep processing elements heavily utilized. While simpler and more portable than direct management of threads, these approaches still entangle program logic with resource management. Similar kinds of highly parallel runtime system have also been developed for functional languages. Here, however, language support for higher-order functions allows a cleaner separation between the algorithm and `skeletons' that express generic patterns of parallel computation. We report results on using this technique to develop a distributed version of the Joint Contour Net, a generalization of the Contour Tree to multifields. We present performance comparisons against a recent Haskell implementation using shared-memory parallelism, and initial work on a skeleton for distributed memory implementation that utilizes an innovative strategy to reduce inter-process communication overheads