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Memorias de investigación
Capítulo de libro:
A model of brightness variations due to illumination changes and non-rigid motion using spherical harmonics
Áreas de investigación
  • Inteligencia artificial
Pixel brightness variations in an image sequence depend both on the objects’ surface reflectance and on the motion of the camera and object. In the case of rigid shapes some proposed models have been very successful explaining the relation among these strongly coupled components. On the other hand, shapes which deform pose new challenges since the relation between pixel brightness variation with non-rigid motion is not yet clear. In this paper, we introduce a new model which describes brightness variations with two inde- pendent components represented as linear basis shapes. Lighting influence is represented in terms of Spherical Harmonics and non-rigid motion as a linear model which represents image coordinates displacement. We then propose an efficient procedure for the estimation of this image model in two distinct steps. First, shape normals and albedo are estimated using standard photo- metric stereo on a sequence with varying lighting and no deformable mo- tion. Then, given the knowledge of the object’s shape normals and albedo, we efficiently compute the 2D coordinates bases by minimizing image pixel residuals over an image sequence with constant lighting and only non-rigid motion. Experiments on real tests show the effectiveness of our approach in a face modelling context.
Edición del Libro
Editorial del Libro
British Machine Vision Association
978 1 901725 37 7
Título del Libro
Proceedings of the British Machine Vision Conference 2008
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Esta actividad pertenece a memorias de investigación
  • Autor: José Miguel Buenaposada Biencit (UPM)
  • Autor: Enrique Muñoz Corral (UPM)
  • Autor: Luis Baumela Molina (UPM)
Grupos de investigación, Departamentos, Centros e Institutos de I+D+i relacionados
  • Creador: Grupo de Investigación: Percepción Computacional y Robótica
  • Departamento: Inteligencia Artificial
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