Image reconstruction through metamorphosis

International audienceThis article adapts the framework of metamorphosis to the resolution of inverse problems with shape prior. The metamorphosis framework allows to transform an image via a balance between geometrical deformations and changes in intensities (that can for instance correspond to the appearance of a new structure). The idea developed here is to reconstruct an image from noisy and indirect observations by registering, via metamorphosis, a template to the observed data. Unlike a registration with only geometrical changes, this framework gives good results when intensities of the template are poorly chosen. We show that this method is a well-defined regularization method (proving existence, stability and convergence) and present several numerical examples

Lagrange-Poincare field equations

The Lagrange-Poincare equations of classical mechanics are cast into a field theoretic context together with their associated constrained variational principle. An integrability/reconstruction condition is established that relates solutions of the original problem with those of the reduced problem. The Kelvin-Noether theorem is formulated in this context. Applications to the isoperimetric problem, the Skyrme model for meson interaction, metamorphosis image dynamics, and molecular strands illustrate various aspects of the theory.Comment: Submitted to Journal of Geometry and Physics, 45 pages, 1 figur

Indirect Image Registration with Large Diffeomorphic Deformations

The paper adapts the large deformation diffeomorphic metric mapping framework for image registration to the indirect setting where a template is registered against a target that is given through indirect noisy observations. The registration uses diffeomorphisms that transform the template through a (group) action. These diffeomorphisms are generated by solving a flow equation that is defined by a velocity field with certain regularity. The theoretical analysis includes a proof that indirect image registration has solutions (existence) that are stable and that converge as the data error tends so zero, so it becomes a well-defined regularization method. The paper concludes with examples of indirect image registration in 2D tomography with very sparse and/or highly noisy data.Comment: 43 pages, 4 figures, 1 table; revise

Metamorphosis and identity : psychoanalytical notes to Miyazaki’s Spirited Away and Howl’s Moving Castle

Far greater liberties can be taken by animation than by live-action films The possibilities of the narratives are enriched by unrestricted visual images that offer unique means of exploring and portraying states of desire, conscious and unconscious realities, as well as different layers of relationships and experiences. This leads to a fusion of the traditional and modern roles of representation. Anime from acclaimed Japanese director Hayao Miyazaki, particularly the Academy Award winner Spirited Away (Sen to Chihiro no Kamikakushi, 2003) and Oscar-nominated Howl’s Moving Castle (Hauru no Ugoku Shiro, 2004), which in recent years have acquired a global cult status, offer new perspectives on human subjectivity. Through their playful use of the motif of transformation, striking similarities in the development of the plots and ambiguous dénouements, the movies problematize the fundamental question of identity, representing a close illustration of some of the core psychoanalytical concepts found in Lacanian theory