Reconstruction of partially sampled EELS images

Etienne Monier (1) , Thomas Oberlin (1) , Nathalie Brun (2) , Maria de Frutos (2) , Marcel Tencé (2) , Nicolas Dobigeon (1, 3)

1 IRIT-SC - Signal et Communications
2 LPS - Laboratoire de Physique des Solides
3 Toulouse INP - Institut National Polytechnique (Toulouse)

Electron microscopy has shown to be a very powerful tool to deeply analyze the chemical composition at various scales. However, many samples can not be analyzed with an acceptable signal-to-noise ratio because of the radiation damage induced by the electron beam. Particularly, electron energy loss spectroscopy (EELS) which acquires a spectrum for each spatial position requires high beam intensity. Scanning transmission electron microscopes (STEM) sequentially acquire data cubes by scanning the electron probe over the sample and record a spectrum for each spatial position. Recent works developed new acquisition procedures, which allow for partial acquisition schemes following a predetermined scan pattern. A reconstruction of the full data cube is conducted as a post-processing step. A multi-band image reconstruction procedure which exploits the spectral structure and the spatial smoothness of STEM-EELS images is explained here. The performance of the proposed scheme is illustrated thanks to experiments conducted on a realistic phantom dataset as well as real EELS spectrum-image.

Mots clés: Electron Energy Loss Spectroscopy EELS; Multi-band imaging; Image reconstruction; Partial sampling; Spectrum-image; Inpainting; Scanning Transmission Electron Microscope STEM

Domaines: Traitement des images [eess.IV]

Etienne Monier, Thomas Oberlin, Nathalie Brun, Maria de Frutos, Marcel Tencé, et al.. Reconstruction of partially sampled EELS images. 9th IEEE Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS 2018), Sep 2018, Amsterdam, Netherlands. ⟨10.1109/WHISPERS.2018.8747104⟩. ⟨hal-02289995⟩