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Proc. of the IEEE International Conference on Image Processing (ICIP2012); 09/2012
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Proc. of the IEEE International Conference on Image Processing (ICIP2012); 09/2012
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SPIE Proc. of Sensing for Agriculture and Food Quality and Safety; 04/2012
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SPIE Proc. of Sensing for Agriculture and Food Quality and Safety; 04/2012
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ABSTRACT: The dynamics of genome regions are associated to the functional or dysfunctional behaviour of the human cell. In order to study these dynamics it is necessary to remove perturbations coming from movement and deformation of the nucleus, i.e. the container holding the genome. In literature models have been proposed to cope with the transformations corresponding to nuclear dynamics of healthy cells. However for pathological cells, the nucleus deforms in an apparently random way, making the use of such models a non trivial task. In this paper we propose a mapping of the cell nucleus which is based on the matching of the nuclear contours. The proposed method does not put constraints on the possible shapes nor on the possible deformations, making this method suited for the analysis of pathological nuclei.
Engineering in Medicine and Biology Society (EMBC), 2010 Annual International Conference of the IEEE; 10/2010
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ABSTRACT: Our surroundings change all the time. Applications that require 3D models of a changing terrain, such as urban planning, are becoming ever more demanding with respect to the cost to create them and the accuracy of the result. A novel, cheap and fast solution for this problem is given by a UAV to take aerial images of the terrain in question, in combination with structure from motion algorithms to create a 3D model from those aerial images. However the question remains whether these on-the-fly 3D maps can match the accuracy of classical surveyor based models, which require more time to create. In this paper we investigate this question, and find that under certain conditions the accuracy of the UAV based model matches the accuracy of surveyor generated measurements.
Geoscience and Remote Sensing Symposium (IGARSS), 2010 IEEE International; 08/2010
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ABSTRACT: Due to weight constraints, UAVs often carry cameras with lenses that create distortions in the image. For practical applications this distortion should be removed with a proper calibration procedure, without spending too much extra time. Existing methods require costly manual interaction when the grid is not fully visible, or when not all points can be extracted. In this paper we present an algorithm to perform the calibration without any user interaction whatsoever, which works under almost all possible conditions. The only inputs are a number of pictures of a checkerboard, taken with the camera. We extract the corners from the chessboard pictures, and set up a world coordinate grid that is robust to missing corner points, occlusion and deformations. We automatically omit the pictures that are too close to another picture, to avoid giving too much weight to often viewed areas. Finally we optimize the result by iteratively removing outlier pictures from the set.
Geoscience and Remote Sensing Symposium,2009 IEEE International,IGARSS 2009; 08/2009
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ABSTRACT: Very high spatial resolution satellite images allow to identify individual man-made objects. However, automatic extraction of these objects is still very difficult, especially in urban areas. Spectral information is insufficient to separate the different man-made object classes. Therefore, there is an increased interest in incorporating shape and contextual information in the classification process. Object-based approaches provide a straightforward method to incorporate both shape and contextual information. However, these approaches require a segmentation of the image, which is a very difficult and sensitive task, especially in urban areas. Recently some attempts have been made to incorporate shape information on a pixel basis. In this paper we further develop this approach and propose a method to also derive contextual information on a pixel basis. The per-pixel features developed in this paper contain information about the distance from the object the pixel belongs to to the nearest shadow object. Clearly, this information can be helpful to identify buildings, which are generally accompanied by shadow. However, the proposed method can also be used to describe other contextual information.
Geoscience and Remote Sensing Symposium, 2008. IGARSS 2008. IEEE International; 08/2008
