Exploring Blob Detection to Determine Atomic Column Positions and Intensities in Time-Resolved TEM Images with Ultra-Low Signal-to-Noise

• Published in: Microscopy and microanalysis Vol. 28; no. 6; pp. 1917 - 1930
• Main Authors: Manzorro, Ramon, Xu, Yuchen, Vincent, Joshua L., Rivera, Roberto, Matteson, David S., Crozier, Peter A.
• Format: Journal Article
• Language: English
• Published: New York, USA Cambridge University Press 01.12.2022; Oxford University Press
• Subjects: Algorithms; Catalysis; Columns (structural); Computer vision; Image analysis; Microscopy; Nanoparticles; Object recognition; Signal processing; Signal to noise ratio; Software and Instrumentation; Temporal resolution; Transmission electron microscopy; tracking algorithm; nanoparticles; blob detection; transmission electron microscopy; noisy; atomic columns; time-resolved TEM
• ISSN: 1431-9276; 1435-8115; 1435-8115
• DOI: 10.1017/S1431927622000356

Spatially resolved in situ transmission electron microscopy (TEM), equipped with direct electron detection systems, is a suitable technique to record information about the atom-scale dynamics with millisecond temporal resolution from materials. However, characterizing dynamics or fluxional behavior requires processing short time exposure images which usually have severely degraded signal-to-noise ratios. The poor signal-to-noise associated with high temporal resolution makes it challenging to determine the position and intensity of atomic columns in materials undergoing structural dynamics. To address this challenge, we propose a noise-robust, processing approach based on blob detection, which has been previously established for identifying objects in images in the community of computer vision. In particular, a blob detection algorithm has been tailored to deal with noisy TEM image series from nanoparticle systems. In the presence of high noise content, our blob detection approach is demonstrated to outperform the results of other algorithms, enabling the determination of atomic column position and its intensity with a higher degree of precision.