Welcome

Hi I’m Lewys Jones, a post-doctoral research associate in the group of Prof. Peter Nellist at the Department of Materials, University of Oxford.

My current research in metrology development is based around exploring the design and function of the aberration-corrected scanning transmission electron microscope (STEM), to improve the analysis of atomic-resolution annular dark-field  (ADF) data and EELS and EDX chemical mapping. Themes include ADF normalisation by detector efficiency, correction of scan-noise and scan-distortion and correction of artefacts in EELS spectra. As part of this research a series of image analysis and processing codes have been written to inspect,  improve and quantify atomic-resolution ADF STEM data.

Astronomical Image Stabilisation in MatLab

Terrestrial telescopes have the unfortunate drawback of having to image through several miles of atmosphere. This can lead to ‘atmospheric distortions’ causing images to appear ‘wobbly’. This effect is most apparent in movies recorded through telescopes.

Here is an example movie of the moon with some common issues including; camera-motion, camera-shake and atmospheric distortion. Movie is best viewed fullscreen, movie credit: DecemberEves.

Now we will correct these issues using the Smart Align registration software. First the video was imported into MatLab, converted to grey-scale and sub-sampled to keep every 10th frame leaving 75 frames.