This repository has been published to Zenodo

Gas Hydrate Segmentation Using U-nets. Code Repository.

This code repository supports the article manuscript entitled 'U-Net Segmentation Methods for Variable-Contrast XCT Images of Methane-Bearing Sand Using Small Training Datasets' Authored by F. J. Alvarez-Borges, O. N. F. King, B. N. Madhusudhan, T. Connolley, M. Basham and S. I. Ahmed. April 2022

Copyright 2022 Diamond Light Source Ltd. Licensed under the Apache License, Version 2.0

Funders: Natural Environment Research Council (UK) grant No. NE/K00008X/1

Description

2d and 3d U-net training and prediction scripts

These can be found in the unet_methods directory. On Linux, For ease of installation and use we recommend downloading the singularity container.

2d methods

For 2d U-net training and prediction, settings are specified by editing the YAML files in unet_2d/settings. Paths for image data (HDF5 format), labels(HDF5 format) and input models are given via the command line.

For 2d U-net training

python train_2d_unet.py path/to/image/data.h5 path/to/corresponding/segmentation/labels.h5

A model will be trained and saved to your working directory

For 2d U-net prediction

python predict_2d_unet.py path/to/model_file.zip path/to/data_for_prediction.h5

A directory of segmented volumes will be saved to your working directory.

3d methods

For 3d U-net training and prediction, settings are specified by editing the YAML files in unet_3d/settings. Paths for image data(HDF5 format), labels(HDF5 format) and input models are also given in the YAML files.

The 3d methods utilise the Torchio library for data sampling and augmentation: Pérez-García, Fernando, Rachel Sparks, and Sebastien Ourselin. ‘TorchIO: A Python Library for Efficient Loading, Preprocessing, Augmentation and Patch-Based Sampling of Medical Images in Deep Learning’. ArXiv:2003.04696 [Cs, Eess, Stat], 9 March 2020. http://arxiv.org/abs/2003.04696.

And the 3d U-net utilises the pytorch-3dunet library: Wolny, Adrian, Lorenzo Cerrone, Athul Vijayan, Rachele Tofanelli, Amaya Vilches Barro, Marion Louveaux, Christian Wenzl, et al. ‘Accurate and Versatile 3D Segmentation of Plant Tissues at Cellular Resolution’. Edited by Christian S Hardtke, Dominique C Bergmann, Dominique C Bergmann, and Moritz Graeff. ELife 9 (29 July 2020): e57613. https://doi.org/10.7554/eLife.57613.

For 3d U-net training

python train_3d_unet.py 

A model will be trained and saved to the directory where your input data resides.

For 3d U-net prediction

python predict_3d_unet.py

A segmented volume will be saved to the directory where your input data resides.

Installation

In order to run the scripts you will need an NVIDIA GPU, ideally with at least 8GB of memory and that supports CUDA 10 or greater. For U-Net segmentation, we recommend using the singularity container.
Otherwise, If you want to install locally, create an Anaconda environment using the unet_environment.yaml file found in unet_methods.

conda env create -n unet_env -f unet_methods/unet_environment.yaml

Once the environment is installed you can activate it

conda activate unet_env

You should now be able to run the U-net training and prediction by calling the relevant scripts using Python.

Singularity Container

Rather than installing your own anaconda environment and downloading the codebase, both can be retrieved in a singularity container.

singularity pull library://ollyking/unet-segmentation/unet_conda_container

To run the container, first a writable data directory needs to be created to be bound to the container. This directory should contain:

• the data and label files for model training
• a subdirectory named unet-settings, this will contain the YAML settings files. This directory can be copied from the repository and is found here.

In addition, the trained models and any predictions will also be output to this folder.

The following examples assume that the data directory was named my_data_dir and sits in the same directory as the singularity image. The container is run with singularity run and the data directory is bound with the commandline argument -B my_data_dir/:/data, this binds it at the location /data within the container. In addition the flag --nv is needed in order to give the container access to the GPU.

For 2d U-net training using the container image

singularity run --nv -B my_data_dir/:/data unet_conda_container_latest.sif 2dunet-train --data /data/<my_data_file.h5> --labels /data/<my_label_file.h5> --data_dir /data

A model will be trained and saved to my_data_dir along with a preview image.

For 2d U-net prediction using the container image

singularity run --nv -B my_data_dir/:/data unet_conda_container_latest.sif 2dunet-predict /data/<my_trained_2d_model.zip> /data/<data_file_to_predict.h5> --data_dir /data

A directory of segmented volumes will be saved to my_data_dir.

For 3d U-net training using the container image

singularity run --nv -B my_data_dir/:/data unet_conda_container_latest.sif 3dunet-train /data/<my_data_file.h5> /data/<my_label_file.h5> /data/<my_validation_data_file.h5> /data/<my_validation_label_file.h5> --data_dir /data

A model will be trained and saved to my_data_dir along with a preview image and a graph of training and validation loss. In addition, a segmentation of the validation volume is saved.

For 3d U-net prediction using the container image

singularity run --nv -B my_data_dir/:/data unet_conda_container_latest.sif 3dunet-predict /data/<my_trained_3d_model.pytorch> /data/<data_file_to_predict.h5> --data_dir /data

The segmented volume will be saved to my_data_dir.

Data preparation and Rootpainter training data scripts

These can be found in the matlab_scripts directory.

For computation of segmentation performance based on the central 40 XY slices: 'segmentation_performance.m'

To convert 572x572x572 voxel training and validation HDF5 subvolumes into RootPainter-readable slices: 'rootpainter_annot_CH4.m' 'rootpainter_annot_sand.m'

To convert HDF5 file data to tiff stacks for visualisation: 'h5_to_tiff_stack.m'

All MATLAB scripts are run using the MATLAB app and include a graphical user interface for file input/output.

MATLAB code was created using MATLAB 2020b.