Non linear phase retrieval from fresnel diffraction patterns using the frechet derivative

B. Sixou (1) , V. Davidoiu (1) , M. Langer (2, 1) , F. Peyrin (1)

1 Imagerie Tomographique et Radiothérapie
2 ESRF - European Synchrotron Radiation Facility

Several methods of phase retrieval for in line phase tomography have already been investigated based on the linearization of the relation between the phase shift induced by the object and the diffracted intensity. They use the Transport Intensity Equation (TIE) or the Contrast Transfer Function (CTF), or mixed approaches. In this work, we present a non linear iterative approach using the Frechet derivative of the intensity recorded at a few number of propagation distances. The inverse problem is regularized with the smoothing L 2 norm of the phase gradient. The evaluation of the method was performed using a simple phase map, both with and without noise. Our approach outerperforms the linear methods on simulated noisy data up to high noise levels.

Mots clés: X-ray Imaging; Coherent Imaging; Phase Contrast; Phase Retrieval; Nonlinear Optimization

Domaines: Imagerie

B. Sixou, V. Davidoiu, M. Langer, F. Peyrin. Non linear phase retrieval from fresnel diffraction patterns using the frechet derivative. IEEE International Symposium on Biomedical Imaging: From Nano to Macro, Mar 2011, Chicago, United States. pp.1370-1373, ⟨10.1109/ISBI.2011.5872655⟩. ⟨hal-01825259⟩