Cage Active Contours for image warping and morphing

Cage Active Contours (CACs) have shown to be a framework for segmenting connected objects using a new class of parametric region-based active contours. The CAC approach deforms the contour locally by moving cage's points through affine transformations. The method has shown good performance for image segmentation, but other applications have not been studied. In this paper, we extend the method with new energy functions based on Gaussian mixture models to capture multiple color components per region and extend their applicability to RGB color space. In addition, we provide an extended mathematical formalization of the CAC framework with the purpose of showing its good properties for segmentation, warping, and morphing. Thus, we propose a multiple-step combined method for segmenting images, warping the correspondences of the object cage points, and morphing the objects to create new images. For validation, both quantitative and qualitative tests are used on different datasets. The results show that the new energies produce improvements over the previously developed energies for the CAC. Moreover, we provide examples of the application of the CAC in image segmentation, warping, and morphing supported by our theoretical conclusions

Els treballs de fi de grau a la Universitat de Barcelona

Podeu consultar la versió castellana al camp recurs relacionat.La implantació dels títols de grau ha suposat un repte per a les universitats, que han hagut d'adaptar els seus projectes formatius a les directrius de l’Espai Europeu d’Educació Superior. Un dels aspectes importants d’aquest procés ha estat l'obligació d’incorporar els treballs de fi de grau (TFG) a l’estructura curricular dels plans d’estudis. Aquesta tasca ha estat complexa i, a més, s’ha vist dificultada per la poca tradició que la majoria de facultats i escoles universitàries tenien en el disseny, l'organització i l'avaluació d’aquest tipus de treball. Uns quants cursos després d’haver-se posat en marxa els TFG, l’Institut de Ciències de l’Educació (ICE) de la Universitat de Barcelona va voler oferir als diferents centres de la UB una plataforma de reflexió i debat on poguessin compartir experiències, plantejar dubtes, analitzar models de bones pràctiques i recollir idees per millorar els seus projectes. A tal efecte, des de la Secció d’Universitat de l’ICE, es va organitzar la jornada «Els treballs de fi de grau a la UB». Aquest quadern recull les comunicacions presentades, sintetitza el debat que van generar i presenta les conclusions a què es va arribar

Los trabajos de fin de grado en la Universidad de Barcelona

Podeu consultar la versió catalana al camp recurs relacionat.[spa] La implantación de los títulos de grado ha supuesto un reto para las universidades, que han tenido que adaptar sus proyectos formativos a las directrices del Espacio Europeo de Educación Superior. Uno de los aspectos importantes de este proceso ha sido la obligación de incorporar los trabajos de fin de grado (TFG) a la estructura curricular de los planes de estudios. Esta tarea ha sido compleja y, además, se ha visto dificultada por la poca tradición que la mayoría de facultades y escuelas universitarias tenían en el diseño, organización y evaluación de esta clase de trabajo. Después de varios cursos de haberse puesto en marcha los TFG, el Instituto de Ciencias de la Educación (ICE) de la Universidad de Barcelona quiso ofrecer a los diferentes centros de la UB una plataforma de reflexión y debate donde pudieran compartir experiencias, plantear dudas, analizar modelos de buenas prácticas y recoger ideas para mejorar sus proyectos. A tal efecto, desde la Sección de Universidad del ICE se organizó la jornada «Los trabajos de fin de grado en la UB». Este cuaderno recoge las comunicaciones presentadas, sintetiza el debate que generaron y presenta las conclusiones a que se llegó.[eng] The phase-in of undergraduate degrees conforming to the guidelines of the European Higher Education Area has been a challenge for universities as far as their training projects are concerned. An important aspect of this process was the need to incorporate the Bachelor’s Degree Final Project (TFG) to the structure of their curricula. This task has been complex and been hampered also by the lack of tradition that most faculties and university colleges had in the design, organization and evaluation of these types of project. Several years after launching the TFG, the Institute of Education Sciences (ICE) of the University of Barcelona (UB) organized the «The Bachelor’s Degree Final Project» conference to offer different centres of the UB a space for reflection and debate to be able to share experiences, ask questions, analyse models of good practices and gather ideas for improving their projects. The present booklet includes papers, summarizes the debate that many and varied contributions generated and outlines the final conclusions reached at this conference

Line search multilevel optimization as computational methods for dense optical flow

We evaluate the performance of different optimization techniques developed in the context of optical flow computation with different variational models. In particular, based on truncated Newton methods (TN) that have been an effective approach for large-scale unconstrained optimization, we de- velop the use of efficient multilevel schemes for computing the optical flow. More precisely, we evaluate the performance of a standard unidirectional mul- tilevel algorithm - called multiresolution optimization (MR/OPT), to a bidrec- tional multilevel algorithm - called full multigrid optimization (FMG/OPT). The FMG/OPT algorithm treats the coarse grid correction as an optimiza- tion search direction and eventually scales it using a line search. Experimental results on different image sequences using four models of optical flow com- putation show that the FMG/OPT algorithm outperforms both the TN and MR/OPT algorithms in terms of the computational work and the quality of the optical flow estimation

Trust region versus line search for computing the optical flow

We consider the numerical treatment of the optical flow problem by evaluating the performance of the trust region method versus the line search method. To the best of our knowledge, the trust region method is studied here for the first time for variational optical flow computation. Four different optical flow models are used to test the performance of the proposed algorithm combining linear and nonlinear data terms with quadratic and TV regularization. We show that trust region often performs better than line search; especially in the presence of non-linearity and non-convexity in the model

Cage Active Contours for image warping and morphing

Cage Active Contours (CACs) have shown to be a framework for segmenting connected objects using a new class of parametric region-based active contours. The CAC approach deforms the contour locally by moving cage's points through affine transformations. The method has shown good performance for image segmentation, but other applications have not been studied. In this paper, we extend the method with new energy functions based on Gaussian mixture models to capture multiple color components per region and extend their applicability to RGB color space. In addition, we provide an extended mathematical formalization of the CAC framework with the purpose of showing its good properties for segmentation, warping, and morphing. Thus, we propose a multiple-step combined method for segmenting images, warping the correspondences of the object cage points, and morphing the objects to create new images. For validation, both quantitative and qualitative tests are used on different datasets. The results show that the new energies produce improvements over the previously developed energies for the CAC. Moreover, we provide examples of the application of the CAC in image segmentation, warping, and morphing supported by our theoretical conclusions

Line search multilevel optimization as computational methods for dense optical flow

We evaluate the performance of different optimization techniques developed in the context of optical flow computation with different variational models. In particular, based on truncated Newton methods (TN) that have been an effective approach for large-scale unconstrained optimization, we de- velop the use of efficient multilevel schemes for computing the optical flow. More precisely, we evaluate the performance of a standard unidirectional mul- tilevel algorithm - called multiresolution optimization (MR/OPT), to a bidrec- tional multilevel algorithm - called full multigrid optimization (FMG/OPT). The FMG/OPT algorithm treats the coarse grid correction as an optimiza- tion search direction and eventually scales it using a line search. Experimental results on different image sequences using four models of optical flow com- putation show that the FMG/OPT algorithm outperforms both the TN and MR/OPT algorithms in terms of the computational work and the quality of the optical flow estimation

Els treballs de fi de grau a la Universitat de Barcelona

Podeu consultar la versió castellana al camp recurs relacionat.La implantació dels títols de grau ha suposat un repte per a les universitats, que han hagut d'adaptar els seus projectes formatius a les directrius de l’Espai Europeu d’Educació Superior. Un dels aspectes importants d’aquest procés ha estat l'obligació d’incorporar els treballs de fi de grau (TFG) a l’estructura curricular dels plans d’estudis. Aquesta tasca ha estat complexa i, a més, s’ha vist dificultada per la poca tradició que la majoria de facultats i escoles universitàries tenien en el disseny, l'organització i l'avaluació d’aquest tipus de treball. Uns quants cursos després d’haver-se posat en marxa els TFG, l’Institut de Ciències de l’Educació (ICE) de la Universitat de Barcelona va voler oferir als diferents centres de la UB una plataforma de reflexió i debat on poguessin compartir experiències, plantejar dubtes, analitzar models de bones pràctiques i recollir idees per millorar els seus projectes. A tal efecte, des de la Secció d’Universitat de l’ICE, es va organitzar la jornada «Els treballs de fi de grau a la UB». Aquest quadern recull les comunicacions presentades, sintetitza el debat que van generar i presenta les conclusions a què es va arribar