Metadata-Version: 2.1
Name: torchio
Version: 0.13.2
Summary: Tools for loading, augmenting and writing 3D medical images on PyTorch.
Home-page: https://github.com/fepegar/torchio
Author: Fernando Perez-Garcia
Author-email: fernando.perezgarcia.17@ucl.ac.uk
License: MIT license
Description: # TorchIO
        
        [![Google Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/drive/112NTL8uJXzcMw4PQbUvMQN-WHlVwQS3i)
        [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.3598622.svg)](https://doi.org/10.5281/zenodo.3598622)
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        `torchio` is a Python package containing a set of tools to efficiently
        read, sample and write 3D medical images in deep learning applications
        written in [PyTorch](https://pytorch.org/),
        including intensity and spatial transforms
        for data augmentation and preprocessing. Transforms include typical computer vision operations
        such as random affine transformations and also domain-specific ones such as
        simulation of intensity artifacts due to
        [MRI magnetic field inhomogeneity](http://mriquestions.com/why-homogeneity.html)
        or [k-space motion artifacts](http://proceedings.mlr.press/v102/shaw19a.html).
        
        This package has been greatly inspired by [NiftyNet](https://niftynet.io/).
        
        
        ## Jupyter notebook
        
        The best way to quickly understand and try the library is the
        [Jupyter notebook](https://colab.research.google.com/drive/112NTL8uJXzcMw4PQbUvMQN-WHlVwQS3i)
        hosted by Google Colab.
        It includes many examples and visualization of most of the classes and even
        training of a [3D U-Net](https://www.github.com/fepegar/unet) for brain
        segmentation of T1-weighted MRI with whole images and patch-based sampling.
        
        
        ## Credits
        
        If you like this repository, please click on Star!
        
        If you used this package for your research, please cite this repository using
        the information available on its
        [Zenodo entry](https://doi.org/10.5281/zenodo.3598622) or use this text:
        
        > Pérez-García, Fernando.
        (2020, January 15).
        fepegar/torchio: TorchIO: Tools for loading, augmenting and writing 3D medical images on PyTorch. Zenodo.
        http://doi.org/10.5281/zenodo.3598622
        
        BibTeX entry:
        
        ```bibtex
        @software{perez_garcia_fernando_2020_3598622,
          author       = {Pérez-García, Fernando},
          title        = {{fepegar/torchio: TorchIO: Tools for loading,
                           augmenting and writing 3D medical images on
                           PyTorch}},
          month        = jan,
          year         = 2020,
          publisher    = {Zenodo},
          doi          = {10.5281/zenodo.3598622},
          url          = {https://doi.org/10.5281/zenodo.3598622}
        }
        ```
        
        
        ## Index
        
        - [Installation](#installation)
        - [Features](#features)
          * [Data handling](#data-handling)
            - [`ImagesDataset`](#imagesdataset)
            - [Samplers and aggregators](#samplers-and-aggregators)
            - [`Queue`](#queue)
          * [Transforms](#transforms)
            - [Augmentation](#augmentation)
              * [Intensity](#intensity)
                - [MRI k-space motion artifacts](#mri-k-space-motion-artifacts)
                - [MRI k-space ghosting artifacts](#mri-k-space-ghosting-artifacts)
                - [MRI k-space spike artifacts](#mri-k-space-spike-artifacts)
                - [MRI magnetic field inhomogeneity](#mri-magnetic-field-inhomogeneity)
                - [Patch swap](#patch-swap)
                - [Gaussian noise](#gaussian-noise)
                - [Gaussian blurring](#gaussian-blurring)
              * [Spatial](#spatial)
                - [B-spline dense elastic deformation](#b-spline-dense-elastic-deformation)
                - [Flip](#flip)
                - [Affine transform](#affine-transform)
            - [Preprocessing](#preprocessing)
              * [Histogram standardization](#histogram-standardization)
              * [Z-normalization](#z-normalization)
              * [Rescale](#rescale)
              * [Resample](#resample)
              * [Pad](#pad)
              * [Crop](#crop)
              * [ToCanonical](#tocanonical)
              * [CenterCropOrPad](#centercroporpad)
            - [Others](#others)
              * [Lambda](#lambda)
        
        
        - [Example](#example)
        - [Related projects](#related-projects)
        - [See also](#see-also)
        
        
        ## Installation
        
        This package is on the
        [Python Package Index (PyPI)](https://pypi.org/project/torchio/).
        To install it, just run in a terminal the following command:
        
        ```shell
        $ pip install torchio
        ```
        
        
        ## Features
        
        ### Data handling
        
        #### [`ImagesDataset`](torchio/data/images.py)
        
        `ImagesDataset` is a reader of 3D medical images that directly inherits from
        [`torch.utils.Dataset`](https://pytorch.org/docs/stable/data.html#torch.utils.data.Dataset).
        It can be used with a
        [`torch.utils.DataLoader`](https://pytorch.org/docs/stable/data.html#torch.utils.data.DataLoader)
        for efficient loading and data augmentation.
        
        It receives a list of subjects, where each subject is an instance of
        [`torchio.Subject`](torchio/data/images.py) containing instances of
        [`torchio.Image`](torchio/data/images.py).
        The paths suffix must be `.nii`, `.nii.gz` or `.nrrd`.
        
        ```python
        import torchio
        from torchio import ImagesDataset, Image, Subject
        
        subject_a = Subject([
            Image('t1', '~/Dropbox/MRI/t1.nrrd', torchio.INTENSITY),
            Image('label', '~/Dropbox/MRI/t1_seg.nii.gz', torchio.LABEL),
        ])
        subject_b = Subject(
            Image('t1', '/tmp/colin27_t1_tal_lin.nii.gz', torchio.INTENSITY),
            Image('t2', '/tmp/colin27_t2_tal_lin.nii', torchio.INTENSITY),
            Image('label', '/tmp/colin27_seg1.nii.gz', torchio.LABEL),
        )
        subjects_list = [subject_a, subject_b]
        subjects_dataset = ImagesDataset(subjects_list)
        subject_sample = subjects_dataset[0]
        ```
        
        
        #### [Samplers and aggregators](torchio/data/sampler/sampler.py)
        
        `torchio` includes grid, uniform and label patch samplers. There is also an
        aggregator used for dense predictions.
        For more information about patch-based training, see
        [NiftyNet docs](https://niftynet.readthedocs.io/en/dev/window_sizes.html).
        
        ```python
        import torch
        import torchio
        
        CHANNELS_DIMENSION = 1
        patch_overlap = 4
        grid_sampler = torchio.inference.GridSampler(
            input_array,  # some NumPy array
            patch_size=128,
            patch_overlap=patch_overlap,
        )
        patch_loader = torch.utils.data.DataLoader(grid_sampler, batch_size=4)
        aggregator = torchio.inference.GridAggregator(
            input_array,
            patch_overlap=patch_overlap,
        )
        
        # Some torch.nn.Module
        model.to(device)
        model.eval()
        with torch.no_grad():
            for patches_batch in patch_loader:
                input_tensor = patches_batch['image'].to(device)
                locations = patches_batch['location']
                logits = model(input_tensor)
                labels = logits.argmax(dim=CHANNELS_DIMENSION, keepdim=True)
                outputs = labels
                aggregator.add_batch(outputs, locations)
        
        output_array = aggregator.output_array
        ```
        
        
        #### [`Queue`](torchio/data/queue.py)
        
        A patches `Queue` (or buffer) can be used for randomized patch-based sampling
        during training.
        [This interactive animation](https://niftynet.readthedocs.io/en/dev/config_spec.html#queue-length)
        can be used to understand how the queue works.
        
        ```python
        import torch
        import torchio
        
        patches_queue = torchio.Queue(
            subjects_dataset=subjects_dataset,  # instance of torchio.ImagesDataset
            max_length=300,
            samples_per_volume=10,
            patch_size=96,
            sampler_class=torchio.sampler.ImageSampler,
            num_workers=4,
            shuffle_subjects=True,
            shuffle_patches=True,
        )
        patches_loader = DataLoader(patches_queue, batch_size=4)
        
        num_epochs = 20
        for epoch_index in range(num_epochs):
            for patches_batch in patches_loader:
                logits = model(patches_batch)  # model is some torch.nn.Module
        ```
        
        
        ### Transforms
        
        The transforms package should remind users of
        [`torchvision.transforms`](https://pytorch.org/docs/stable/torchvision/transforms.html).
        They take as input the samples generated by an [`ImagesDataset`](#dataset).
        
        A transform can be quickly applied to an image file using the command-line
        tool `torchio-transform`:
        
        ```shell
        $ torchio-transform input.nii.gz RandomMotion output.nii.gz --kwargs "proportion_to_augment=1 num_transforms=4"
        ```
        
        #### Augmentation
        
        ##### Intensity
        
        ###### [MRI k-space motion artifacts](torchio/transforms/augmentation/intensity/random_motion.py)
        
        Magnetic resonance images suffer from motion artifacts when the subject moves
        during image acquisition. This transform follows
        [Shaw et al., 2019](http://proceedings.mlr.press/v102/shaw19a.html) to
        simulate motion artifacts for data augmentation.
        
        ![MRI k-space motion artifacts](https://raw.githubusercontent.com/fepegar/torchio/master/images/random_motion.gif)
        
        
        ###### [MRI k-space ghosting artifacts](torchio/transforms/augmentation/intensity/random_ghosting.py)
        
        Discrete "ghost" artifacts may occur along the phase-encode direction whenever the position or signal intensity of imaged structures within the field-of-view vary or move in a regular (periodic) fashion.
        Pulsatile flow of blood or CSF, cardiac motion, and respiratory motion are the most important patient-related causes of ghost artifacts in clinical MR imaging (From [mriquestions.com](http://mriquestions.com/why-discrete-ghosts.html)).
        
        ![MRI k-space ghosting artifacts](https://raw.githubusercontent.com/fepegar/torchio/master/images/random_ghosting.gif)
        
        
        ###### [MRI k-space spike artifacts](torchio/transforms/augmentation/intensity/random_spike.py)
        
        Also known as [Herringbone artifact](https://radiopaedia.org/articles/herringbone-artifact?lang=gb), crisscross artifact or corduroy artifact,
        it creates stripes in different directions in image space due to spikes in k-space.
        
        ![MRI k-space spike artifacts](https://raw.githubusercontent.com/fepegar/torchio/master/images/random_spike.gif)
        
        
        ###### [MRI magnetic field inhomogeneity](torchio/transforms/augmentation/intensity/random_bias_field.py)
        
        MRI magnetic field inhomogeneity creates slow frequency intensity variations.
        This transform is very similar to the one in
        [NiftyNet](https://niftynet.readthedocs.io/en/dev/niftynet.layer.rand_bias_field.html).
        
        ![MRI bias field artifacts](https://raw.githubusercontent.com/fepegar/torchio/master/images/random_bias_field.gif)
        
        
        ##### [Patch swap](torchio/transforms/augmentation/intensity/random_swap.py)
        
        Randomly swaps patches in the image.
        This is typically done for
        [context restoration for self-supervised learning](https://www.sciencedirect.com/science/article/pii/S1361841518304699).
        
        ![Random patches swapping](https://raw.githubusercontent.com/fepegar/torchio/master/images/random_swap.jpg)
        
        
        ###### [Gaussian noise](torchio/transforms/augmentation/intensity/random_noise.py)
        
        Adds noise sampled from a normal distribution with mean 0 and standard
        deviation sampled from a uniform distribution in the range `std_range`.
        It is often used after [`ZNormalization`](#z-normalization), as the output of
        this transform has zero-mean.
        
        ![Random Gaussian noise](https://raw.githubusercontent.com/fepegar/torchio/master/images/random_noise.gif)
        
        
        ###### [Gaussian blurring](torchio/transforms/augmentation/intensity/random_blur.py)
        
        Blurs the image using a
        [discrete Gaussian image filter](https://itk.org/Doxygen/html/classitk_1_1DiscreteGaussianImageFilter.html).
        
        
        ##### Spatial
        
        ###### [B-spline dense elastic deformation](torchio/transforms/augmentation/spatial/random_elastic_deformation.py)
        <p align="center">
          <img src="https://raw.githubusercontent.com/fepegar/torchio/master/images/random_elastic_deformation.gif" alt="Random elastic deformation"/>
        </p>
        
        
        ###### [Flip](torchio/transforms/augmentation/spatial/random_flip.py)
        
        Reverse the order of elements in an image along the given axes.
        
        
        ###### [Affine transform](torchio/transforms/augmentation/spatial/random_affine.py)
        
        Random affine transformation of the image keeping center invariant.
        
        
        #### Preprocessing
        
        ##### [Histogram standardization](torchio/transforms/preprocessing/intensity/histogram_standardization.py)
        
        Implementation of
        [*New variants of a method of MRI scale standardization*](https://ieeexplore.ieee.org/document/836373)
        adapted from NiftyNet.
        
        ![Histogram standardization](https://raw.githubusercontent.com/fepegar/torchio/master/images/histogram_standardization.png)
        
        
        ##### [Rescale](torchio/transforms/preprocessing/intensity/rescale.py)
        
        Rescale intensity values in an image to a certain range.
        
        
        ##### [Z-normalization](torchio/transforms/preprocessing/intensity/z_normalization.py)
        
        This transform first extracts the values with intensity greater than the mean,
        which is an approximation of the foreground voxels.
        Then the foreground mean is subtracted from the image and it is divided by the
        foreground standard deviation.
        
        
        ##### [Resample](torchio/transforms/preprocessing/spatial/resample.py)
        
        Resample images to a new voxel spacing using `nibabel`.
        
        
        ##### [Pad](torchio/transforms/preprocessing/spatial/pad.py)
        
        Pad images, like in [`torchvision.transforms.Pad`](https://pytorch.org/docs/stable/torchvision/transforms.html#torchvision.transforms.Pad).
        
        
        ##### [Crop](torchio/transforms/preprocessing/spatial/crop.py)
        
        Crop images passing 1, 3, or 6 integers, as in [Pad](#pad).
        
        
        ##### [ToCanonical](torchio/transforms/preprocessing/spatial/to_canonical.py)
        
        Reorder the data so that it is closest to canonical NIfTI (RAS+) orientation.
        
        
        ##### [CenterCropOrPad](torchio/transforms/preprocessing/spatial/center_crop_pad.py)
        
        Crops or pads image center to a target size, modifying the affine accordingly.
        
        
        #### Others
        
        ##### [Lambda](torchio/transforms/lambda_transform.py)
        
        Applies a user-defined function as transform.
        For example, image intensity can be inverted with
        `Lambda(lambda x: -x, types_to_apply=[torchio.INTENSITY])`
        and a mask can be negated with
        `Lambda(lambda x: 1 - x, types_to_apply=[torchio.LABEL])`.
        
        
        
        ## [Example](examples/example_queue.py)
        
        This example shows the improvement in performance when multiple workers are
        used to load and preprocess the volumes using multiple workers.
        
        ```python
        import time
        import multiprocessing as mp
        
        from tqdm import trange
        
        import torch.nn as nn
        from torch.utils.data import DataLoader
        from torchvision.transforms import Compose
        
        from torchio import ImagesDataset, Queue, DATA
        from torchio.data.sampler import ImageSampler
        from torchio.utils import create_dummy_dataset
        from torchio.transforms import (
            ZNormalization,
            RandomNoise,
            RandomFlip,
            RandomAffine,
        )
        
        
        # Define training and patches sampling parameters
        num_epochs = 4
        patch_size = 128
        queue_length = 400
        samples_per_volume = 10
        batch_size = 4
        
        class Network(nn.Module):
            def __init__(self):
                super().__init__()
                self.conv = nn.Conv3d(
                    in_channels=1,
                    out_channels=3,
                    kernel_size=3,
                )
            def forward(self, x):
                return self.conv(x)
        
        model = Network()
        
        # Create a dummy dataset in the temporary directory, for this example
        subjects_list = create_dummy_dataset(
            num_images=100,
            size_range=(193, 229),
            force=False,
        )
        
        # Each element of subjects_list is an instance of torchio.Subject:
        # subject = Subject(
        #     torchio.Image('one_image', path_to_one_image, torchio.INTENSITY),
        #     torchio.Image('another_image', path_to_another_image, torchio.INTENSITY),
        #     torchio.Image('a_label', path_to_a_label, torchio.LABEL),
        # )
        
        # Define transforms for data normalization and augmentation
        transforms = (
            ZNormalization(),
            RandomNoise(std_range=(0, 0.25)),
            RandomAffine(scales=(0.9, 1.1), degrees=10),
            RandomFlip(axes=(0,)),
        )
        transform = Compose(transforms)
        subjects_dataset = ImagesDataset(subjects_list, transform)
        
        
        # Run a benchmark for different numbers of workers
        workers = range(mp.cpu_count() + 1)
        for num_workers in workers:
            print('Number of workers:', num_workers)
        
            # Define the dataset as a queue of patches
            queue_dataset = Queue(
                subjects_dataset,
                queue_length,
                samples_per_volume,
                patch_size,
                ImageSampler,
                num_workers=num_workers,
            )
            batch_loader = DataLoader(queue_dataset, batch_size=batch_size)
        
            start = time.time()
            for epoch_index in trange(num_epochs, leave=False):
                for batch in batch_loader:
                    # The keys of batch have been defined in create_dummy_dataset()
                    inputs = batch['one_modality'][DATA]
                    targets = batch['segmentation'][DATA]
                    logits = model(inputs)
            print('Time:', int(time.time() - start), 'seconds')
            print()
        ```
        
        
        Output:
        ```python
        Number of workers: 0
        Time: 394 seconds
        
        Number of workers: 1
        Time: 372 seconds
        
        Number of workers: 2
        Time: 278 seconds
        
        Number of workers: 3
        Time: 259 seconds
        
        Number of workers: 4
        Time: 242 seconds
        ```
        
        
        ## Related projects
        
        * [Albumentations](https://github.com/albumentations-team/albumentations)
        * [`batchgenerators`](https://github.com/MIC-DKFZ/batchgenerators)
        * [kornia](https://kornia.github.io/)
        * [DALI](https://developer.nvidia.com/DALI)
        * [`rising`](https://github.com/PhoenixDL/rising)
        
        
        ## See also
        
        * [`highresnet`](https://www.github.com/fepegar/highresnet)
        * [`unet`](https://www.github.com/fepegar/unet)
        
        
        =======
        History
        =======
        
        0.2.0 (2019-12-06)
        ------------------
        
        * First release on PyPI.
        
        
        0.3.0 (21-12-2019)
        ------------------
        
        * Add Rescale transform
        * Add support for multimodal data and missing modalities
        
        
        0.4.0 (29-12-2019)
        ------------------
        
        * Add MRI k-space motion artefact augmentation
        
        
        0.5.0 (01-01-2020)
        ------------------
        
        * Add bias field transform
        
        
        0.6.0 (02-01-2020)
        ------------------
        
        * Add support for NRRD
        
        
        0.7.0 (02-01-2020)
        ------------------
        
        * Make transforms use PyTorch tensors consistently
        
        
        0.8.0 (11-01-2020)
        ------------------
        
        * Add Image class
        
        
        0.9.0 (14-01-2020)
        ------------------
        
        * Add CLI tool to transform an image from file
        
        
        0.10.0 (15-01-2020)
        -------------------
        
        * Add Pad transform
        * Add Crop transform
        
        
        0.11.0 (15-01-2020)
        -------------------
        
        * Add Resample transform
        
        
        0.12.0 (21-01-2020)
        -------------------
        
        * Add ToCanonical transform
        * Add CenterCropOrPad transform
        
        
        0.13.0 (24-02-2020)
        -------------------
        
        * Add Subject class
        * Add random blur transform
        * Add lambda transform
        * Add random patches swapping transform
        * Add MRI k-space ghosting artefact augmentation
        
Keywords: torchio
Platform: UNKNOWN
Classifier: Development Status :: 2 - Pre-Alpha
Classifier: Intended Audience :: Science/Research
Classifier: License :: OSI Approved :: MIT License
Classifier: Natural Language :: English
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Requires-Python: >=3.6
Description-Content-Type: text/markdown
