Improving electron micrograph signal-to-noise with an atrous convolutional encoder-decoder

Ultramicroscopy. 2019 Jul:202:18-25. doi: 10.1016/j.ultramic.2019.03.017. Epub 2019 Mar 26.

Abstract

We present an atrous convolutional encoder-decoder trained to denoise electron micrographs. It consists of a modified Xception backbone, atrous convoltional spatial pyramid pooling module and a multi-stage decoder. Our neural network was trained end-to-end using 512 × 512 micrographs created from a large dataset of high-dose ( > 2500 counts per pixel) micrographs with added Poisson noise to emulate low-dose ( ≪ 300 counts per pixel) data. It was then fine-tuned for high dose data (200-2500 counts per pixel). Its performance is benchmarked against bilateral, Gaussian, median, total variation, wavelet, and Wiener restoration methods with their default parameters. Our network outperforms their best mean squared error and structural similarity index performances by 24.6% and 9.6% for low doses and by 43.7% and 5.5% for high doses. In both cases, our network's mean squared error has the lowest variance. Source code and links to our high-quality dataset and pre-trained models are available at https://github.com/Jeffrey-Ede/Electron-Micrograph-Denoiser.

Keywords: Deep learning; Denoising; Electron microscopy; Low dose.