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This thesis explores the relation between module categories over small differential graded (abbreviated DG) categories on the one hand, and well generated triangulated categories on the other. In the first part, we construct the $\alpha$-continuous derived category D_\alpha A of a homotopically $\alpha$-cocomplete small DG category A, where $\alpha$ is a regular cardinal. This construction enjoys a useful and beautiful property which is the key technical result for proving the main theorem of the thesis. The categories D_\alpha A turn out to be the prototypes of the $\alpha$-compactly generated algebraic triangulated categories. Here algebraic means triangle equivalent to the stable category of a Frobenius category. The main result says that algebraic well generated categories are precisely those which are localizations of the derived category of some small DG category. This result is strongly reminiscent of a 1964 theorem of Gabriel and Popescu, which characterized the Grothendieck abelian categories as localizations of categories of modules over rings. It also gives a positive answer to Drinfeld?s question whether all well generated categories arise as localizations of compactly generated ones, for the class of algebraic triangulated categories. In the second part, we study the categories DA and D_\alpha A using the projective Quillen?s model category structure present on the category of DG modules. We introduce the subcategory of homotopically $\alpha$-compact cofibrant DG modules and we show that its homotopy category is precisely the $\alpha$-continuous derived category D_\alpha A. This enables us to give a second, completely different proof of the key technical result of the first part., Cette thèse explore la relation entre les catégories de modules sur les catégories différentielles graduées (abrégées DG) petites, d'une part, et les catégories triangulées bien engendrées d'autre part. Dans la première partie, on construit la catégorie dérivée $\alpha$-continue D_\alpha A d'une catégorie DG $\alpha$-cocomplète petite A, où $\alpha$ est un cardinal régulier. Cette construction jouit d'une propriété très intéressante, qui est la clef pour démontrer le théorème principal de la thèse. Les catégories D_\alpha A s'avèrent être les prototypes des catégories triangulées algébriques à engendrement $\alpha$-compact. On entend par algébrique, équivalente, en tant que catégorie triangulée à la catégorie stable d'une catégorie de Frobenius. Le résultat principal établit que les catégories algébriques bien engendrées sont précisément celles qui sont des localisations de la catégorie dérivée d'une catégorie DG petite. Ce résultat rappelle beaucoup un théorème de Gabriel et Popescu de 1964, qui caractérise les catégories abéliennes de Grothendieck comme des localisations de catégories de modules sur des anneaux. Il donne aussi une réponse positive à une question de Drinfeld qui demandait si toutes les catégories triangulées bien engendrées sont des localisations de catégories triangulées à engendrement compact, pour la classe des catégories triangulées algébriques. Dans la deuxième partie, on étudie les catégories DA et D_\alpha A en utilisant la structure projective de catégories de modèles de Quillen présente sur la catégorie des DG modules. On introduit la sous-catégorie des DG modules cofibrants homotopiquement $\alpha$-compacts et on montre que sa catégorie homotopique est précisément la catégorie dérivée $\alpha$-continue D_\alpha A. Cela nous permet de donner une deuxième preuve, complètement différente du résultat-clef de la première partie.

In the last years numerous applications of Human- Computer Interaction have exploited the capabilities of Time-of- Flight cameras for achieving more and more comfortable and precise interactions. In particular, gesture recognition is one of the most active fields. This work presents a new method for interacting with a virtual object in a 3D space. Our approach is based on the fusion of depth data, supplied by a ToF camera, with color information, supplied by a HD webcam. The hand detection procedure does not require any learning phase and is able to concurrently manage gestures of two hands. The system is robust to the presence in the scene of other objects or people, thanks to the use of the Kalman filter for maintaining the tracking of the hands., {"references":["T. Oggier, M. Lehmann, K. R., M. Schweizer, M. Richter, P. Metzler,\nG. Lang, F. Lustenberger, and N. Blanc, \"An all-solid-state optical range\ncamera for 3D real-time imaging with sub-centimeter depth resolution\n(SwissRanger),\" in Proceeding of SPIE Vol. 5249, 2003, pp. 634-645.","A. Kolb, E. Barth, R. Koch, and R. Larsen, \"Time-of-Flight Cameras\nin Computer Graphics,\" Computer Graphics Forum, vol. 29, no. 1, pp.\n141-159, 2010.","P. Dondi, L. Lombardi, and M. Porta, \"Human-Computer Interaction\nthrough Time-of-Flight and RGB cameras,\" in Proceedings of ICIAP\n2011, 16th International Conference on Image Analysis and Processing,\nvol. 2. Springer, September 2011, pp. 89-98.","R. Reulke, \"Combination of distance data with high resolution images,\"\nin Proceedings of IEVM06, Image Engeeniring and Vision Metrology,\n2006.","S. Ghobadi, O. Loepprich, K. Hartmann, and O. Loffeld, \"Hand segmentation\nusing 2D/3D images,\" in Proceedings of Image and Vision\nComputing 07, December 2007, pp. 64-69.","S. E. Ghobadi, O. E. Loepprich, F. Ahmadov, J. Bernshausen, K. Hartmann,\nand O. Loffeld, \"Real time hand based robot control using 2D/3D\nimages,\" in Proceedings of the 4th International Symposium on Advances\nin Visual Computing, Part II, ser. ISVC -08. Berlin, Heidelberg:\nSpringer-Verlag, 2008, pp. 307-316.","P. Breuer, C. Eckes, and S. Mller, \"Hand gesture recognition with a\nnovel IR time-of-flight range camera: a pilot study,\" in Proceedings\nof 3rd International Conference on Computer vision/computer graphics\ncollaboration techniques (MIRAGE-07), 2007, pp. 247-260.","Z. Li and R. Jarvis, \"Visual interpretation of natural pointing gestures\nin 3d space for human-robot interaction,\" in Proceedings of Control Automation\nRobotics Vision (ICARCV), 2010 11th International Conference\non, December 2010, pp. 2513-2518.","A. Treskunov, S. Kim, and S. Marti, \"Range camera for simple behind\ndisplay interaction,\" in Proceedings of MVA2011 IAPR Conference on\nMachine Vision Applications, Nara, Japan, June 2011, pp. 160-163.\n[10] E. Kollorz, J. Penne, J. Hornegger, and A. Barke, \"Gesture recognition\nwith a time of flight camera,\" Int. J. Intell. Syst. Technol. Appl., vol. 5,\npp. 334-343, November 2008.\n[11] M. B. Holte, T. B. Moeslund, and P. Fihl, \"View invariant gesture\nrecognition using the csem swissranger sr-2 camera,\" Int. J. Intell. Syst.\nTechnol. Appl., vol. 5, pp. 295-303, November 2008.\n[12] M. Van den Bergh and L. Van Gool, \"Combining RGB and ToF cameras\nfor real-time 3D hand gesture interaction,\" in Applications of Computer\nVision (WACV), 2011 IEEE Workshop on, January 2011, pp. 66-72.\n[13] M. Haker, M. Bhme, T. Martinetz, and E. Barth, \"Deictic gestures\nwith a time-of-flight camera,\" in Proceedings of Gesture in Embodied\nCommunication and Human-Computer Interaction 8th International\nGesture Workshop, GW 2009, S. Kopp and I. Wachsmuth, Eds., January\n2009, pp. 110-121.\n[14] T. Oggier, B. Bttgen, F. Lustenberger, G. Becker, B. Regg, and A. Hodac,\n\"Swissranger SR3000 and first experiences based on miniaturized 3DTOF\ncameras,\" in Proceedings, 1st Range Imaging Research Day.\nSpringer, September 2005, pp. 97-108.\n[15] N. Haubner, U. Schwanecke, R. Drner, S. Lehmann, and J. Luderschmidt,\n\"Recognition of Dynamic Hand Gestures with Time-of-Flight\nCameras,\" in Proceedings of ITG/GI Workshop on Self-Integrating\nSystems for Better Living Environments 2010 (Sensyble Workshop),\n2010, pp. 33-39.\n[16] S. Soutschek, J. Penne, J. Hornegger, and J. Kornhuber, \"3-D gesturebased\nscene navigation in medical imaging applications using timeof-\nflight cameras,\" in Proceedings of Computer Vision and Pattern\nRecognition Workshops, 2008. CVPRW -08. IEEE Computer Society\nConference on, June 2008, pp. 1-6.\n[17] J. Penne, S. Soutschek, L. Fedorowicz, and J. Hornegger, \"Robust\nreal-time 3D time-of-flight based gesture navigation,\" in Proceedings\nof Automatic Face Gesture Recognition, 2008. FG -08. 8th IEEE\nInternational Conference on, September 2008, pp. 1-2.\n[18] P. Dondi and L. Lombardi, \"Fast real-time segmentation and tracking of\nmultiple subjects by time-of-flight camera,\" in Proceedings of VISAPP\n2011, 6th International Conference on Computer Vision Theory and\nApplications, March 2011, pp. 582-587."]}