ISP Seminars

{ "name":"Interpolation on Riemannian manifolds with a {$C^1$} piecewize Bézier path", "description":"Nowadays, more and more problems are solved through specific manifold formulation. This often allows important reduction of computation time and/or memory management compared to classical formulations on the classical Euclidean space (because of non-linear constraints like restricting the solutions to a certain subdomain of a larger ambiant space). Interpolation and optimization tools can be useful for solving some of these problems (like defining the optimal trajectory of a humanitory plane dropping supplies, or fitting two objects orientations). However, current procedures are only defined on the Euclidean space. In this presentation, I focus on interpolation methods and, more precisely, I propose a new general framework to fit a path through a finite set of data points lying on a Riemannian manifold. The path takes the form of a continuously-differentiable concatenation of Riemannian Bézier segments. This framework will be illustrated by results on the Euclidean space, the sphere, the orthogonal group and the shape manifold.​ The content of this presentation meets also very recent research carried out in this institute for providing novel efficient manifold-based optimization methods.", "startDate":"2014-10-08", "endDate":"2014-10-08", "startTime":"10:00", "endTime":"10:45", "location":"Nyquist Seminar Room (a164, close to Shannon seminar room) Place du Levant 3, Maxwell Building, 1st floor", "label":"Add to my Calendar", "options":[ "Apple", "Google", "iCal", "Microsoft365", "MicrosoftTeams", "Outlook.com" ], "timeZone":"Europe/Berlin", "trigger":"click", "inline":true, "listStyle":"modal", "iCalFileName":"Seminar-Reminder" }

{ "name":"Spectral clustering techniques for biological data", "description":"Earlier biological studies have shown a strong correlation between the structure of the nucleolus of a cell and the potential diseases affecting this cell. The biologist have generated a database by annihilating some specific genes of the cells and they have visually observed different conformations of the nucleolus. They are interested in grouping (clustering) the cells based on the conformation of their nucleolus. During this presentation, the spectral clustering techniques will be presented and applied on the biological data. After an image analysis processing, each cell is represented by a characteristics' vector. Those vectors are used to build a similarity matrix. The spectral graph theory is then performed to cluster the data. Results on both artificial and real data will be discuss.", "startDate":"2014-09-17", "endDate":"2014-09-17", "startTime":"10:00", "endTime":"10:45", "location":"Shannon Seminar Room (a105) Place du Levant 3, Maxwell Building, 1st floor", "label":"Add to my Calendar", "options":[ "Apple", "Google", "iCal", "Microsoft365", "MicrosoftTeams", "Outlook.com" ], "timeZone":"Europe/Berlin", "trigger":"click", "inline":true, "listStyle":"modal", "iCalFileName":"Seminar-Reminder" }

{ "name":"How using DCE-MRI and registration to measure the concentration of the contrast agent ([CA]) inside the human and guinea-pigs (GP) cochlea?", "description":"How using DCE-MRI and registration to measure the concentration of the contrast agent (CA) inside the human and guinea-pigs (GP) cochlea? Due to the tightness of the blood-labyrinth barrier (BLB) few medium contrast reaches the inner ear resulting to a low received signal. Furthermore, the sizes of the different compartments inside the ear require a good spatial resolution. We are currently trying to design some T1-weigthed MRI sequences and a protocol to quantify the amount of CA along the time. We have performed two classes of experiments. Firstly by using a 4.7T scanner and GP and secondly using a Siemens 3T scanner and human controls. Primarily results highlight a BLB's porosity change in GP with ear infections. Also, we are currently using registration to precisely and automatically quantify the concentration of CA in the different compartments.", "startDate":"2014-09-01", "endDate":"2014-09-01", "startTime":"11:00", "endTime":"11:45", "location":"TVNUM Seminar Room (a124) Place du Levant 2, Stévin Building, 1st floor", "label":"Add to my Calendar", "options":[ "Apple", "Google", "iCal", "Microsoft365", "MicrosoftTeams", "Outlook.com" ], "timeZone":"Europe/Berlin", "trigger":"click", "inline":true, "listStyle":"modal", "iCalFileName":"Seminar-Reminder" }

{ "name":"Single shot depth and image using engineered point spread function", "description":"(please, login to read it)", "startDate":"2014-05-07", "endDate":"2014-05-07", "startTime":"10:00", "endTime":"10:45", "location":"TVNUM Seminar Room (a124) Place du Levant 2, Stévin Building, 1st floor", "label":"Add to my Calendar", "options":[ "Apple", "Google", "iCal", "Microsoft365", "MicrosoftTeams", "Outlook.com" ], "timeZone":"Europe/Berlin", "trigger":"click", "inline":true, "listStyle":"modal", "iCalFileName":"Seminar-Reminder" }

{ "name":"Sensing matrix design criteria for adaptive compressed sensing", "description":"The quest for optimal sensing operators is crucial in the design of efficient architectures that perform compressive sampling of analog signals. While exact theoretical results exist for general sensing operators that guarantee the recovery of sparse signals, such guarantees are strict and often neglected in practical implementations. Moreover, natural signals are only approximately sparse, but often exhibit correlation properties that suggest a further possible optimization of the sensing operator under some signal-domain priors.", "startDate":"2014-04-23", "endDate":"2014-04-23", "startTime":"10:00", "endTime":"10:45", "location":"Shannon Seminar Room (a105) Place du Levant 3, Maxwell Building, 1st floor", "label":"Add to my Calendar", "options":[ "Apple", "Google", "iCal", "Microsoft365", "MicrosoftTeams", "Outlook.com" ], "timeZone":"Europe/Berlin", "trigger":"click", "inline":true, "listStyle":"modal", "iCalFileName":"Seminar-Reminder" }

{ "name":"Which features to discriminate nucleolus phenotypes?", "description":"Earlier biological studies have shown a strong correlation between the structure of the nucleolus of a cell and the potential diseases affecting this cell. During this presentation, I will present a set of 'few' features, based on the shape and the texture of the nucleolus, that might help to discriminate nucleolus phenotypes.", "startDate":"2014-04-02", "endDate":"2014-04-02", "startTime":"10:00", "endTime":"10:45", "location":"Shannon Seminar Room (a105) Place du Levant 3, Maxwell Building, 1st floor", "label":"Add to my Calendar", "options":[ "Apple", "Google", "iCal", "Microsoft365", "MicrosoftTeams", "Outlook.com" ], "timeZone":"Europe/Berlin", "trigger":"click", "inline":true, "listStyle":"modal", "iCalFileName":"Seminar-Reminder" }

{ "name":"Using Shape Priors to Regularize Intermediate Views in Wide-Baseline Image-Based Rendering", "description":"Nowadays, when a viewer watches a video content, his/her viewpoint is fixed to one of the cameras that have recorded the scene. In order to increase the viewer's immersivity, the next generation of video content will allow him/her to interactively define his/her viewpoint. This domain is known as free-viewpoint rendering, and consists of the interpolation of views from images captured by some real cameras. However, the state-of-the-art solutions require that the real cameras share very similar viewpoints, meaning that a close scene can be rendered only with a dense camera network, and that far scenes can be rendered only with very high-resolution cameras. These requirements make free-viewpoint rendering an expensive technology, slowing down its entry on the market.", "startDate":"2014-03-19", "endDate":"2014-03-19", "startTime":"10:00", "endTime":"10:45", "location":"Shannon Seminar Room (a105) Place du Levant 3, Maxwell Building, 1st floor", "label":"Add to my Calendar", "options":[ "Apple", "Google", "iCal", "Microsoft365", "MicrosoftTeams", "Outlook.com" ], "timeZone":"Europe/Berlin", "trigger":"click", "inline":true, "listStyle":"modal", "iCalFileName":"Seminar-Reminder" }

{ "name":"Planar Tracking for 3-D Reconstruction", "description":"This talk presents a tracking method for 3-D reconstruction of planar surfaces in the context of video editing. Interaction with end-user is allowed in order to avoid occlusion of the tracked objects and to correct possible errors. The method takes into account all perspective transformations by a template matching method. This one proceeds first by estimating translation and rotation of the object from large templates before to estimate the perspective transformation with more localized template matching.", "startDate":"2014-03-05", "endDate":"2014-03-05", "startTime":"10:00", "endTime":"10:45", "location":"Shannon Seminar Room (a105) Place du Levant 3, Maxwell Building, 1st floor", "label":"Add to my Calendar", "options":[ "Apple", "Google", "iCal", "Microsoft365", "MicrosoftTeams", "Outlook.com" ], "timeZone":"Europe/Berlin", "trigger":"click", "inline":true, "listStyle":"modal", "iCalFileName":"Seminar-Reminder" }

{ "name":"Adaptability to Improve Convergence", "description":"Optimization techniques have been used extensively throughout signal processing in many applications. One of the key challenges when implementing iterative optimization algorithms is to appropriately choose the step size(s) to improve the algorithm convergence. This pre- sentation is dedicated to the general problem of adaptive selecting the step size based on the works of Aghazadeh et al. [1] and Goldstein et al. [2]. In a first level, the presentation is focused on general iterative algorithms with only one step size, which can be adaptively selected via the ski rental problem [1], a popular class of problems from the computer science literature. In a second level, we discuss about the adaptivity of primal-dual algorithms, where the convergence is sensitive to two step sizes. The two parameters are automatically selected based on the optimality conditions of the problem [2, 3].", "startDate":"2014-02-19", "endDate":"2014-02-19", "startTime":"10:00", "endTime":"10:45", "location":"Shannon Seminar Room (a105) Place du Levant 3, Maxwell Building, 1st floor", "label":"Add to my Calendar", "options":[ "Apple", "Google", "iCal", "Microsoft365", "MicrosoftTeams", "Outlook.com" ], "timeZone":"Europe/Berlin", "trigger":"click", "inline":true, "listStyle":"modal", "iCalFileName":"Seminar-Reminder" }

{ "name":"Compressed sensing methods for cardiac C-arm computed tomography", "description":"In cardiac C-arm CT, electrocardiogram gating leads to a limited view reconstruction problem. Few projections are available to reconstruct each phase, and their angular distribution is not optimal. In such conditions, traditional reconstruction algorithms like SART or FDK prove insufficient. Compressed sensing allows using a priori information in the reconstruction, potentially compensating for the loss of information caused by ECG-gating. This talk will be a quick tour of the 3D compressed sensing methods available for cardiac C-arm CT and of the 3D+time methods developed during my PhD thesis.", "startDate":"2014-02-05", "endDate":"2014-02-05", "startTime":"10:00", "endTime":"10:40", "location":"Shannon Seminar Room (a105) Place du Levant 3, Maxwell Building, 1st floor", "label":"Add to my Calendar", "options":[ "Apple", "Google", "iCal", "Microsoft365", "MicrosoftTeams", "Outlook.com" ], "timeZone":"Europe/Berlin", "trigger":"click", "inline":true, "listStyle":"modal", "iCalFileName":"Seminar-Reminder" }