pathml 3.0.4
Tools for computational pathology

🤖🔬 **PathML: Tools for computational pathology**

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⭐ **PathML objective is to lower the barrier to entry to digital pathology**

Imaging datasets in cancer research are growing exponentially in both quantity and information density. These massive datasets may enable derivation of insights for cancer research and clinical care, but only if researchers are equipped with the tools to leverage advanced computational analysis approaches such as machine learning and artificial intelligence. In this work, we highlight three themes to guide development of such computational tools: scalability, standardization, and ease of use. We then apply these principles to develop PathML, a general-purpose research toolkit for computational pathology. We describe the design of the PathML framework and demonstrate applications in diverse use cases. 

🚀 **The fastest way to get started?**

    docker pull pathml/pathml && docker run -it -p 8888:8888 pathml/pathml

Done, what analyses can I write now? 👉 <a href="https://chat.openai.com/g/g-L1IbnIIVt-digital-pathology-assistant-v3-0" target="_blank"><img src="https://github.com/Dana-Farber-AIOS/pathml/assets/25375373/7fdc35b4-fede-431b-a8d5-324bea1873e4" width="30%"/></a>

<table> 
<tr>
    <td> <img src="https://github.com/Dana-Farber-AIOS/pathml/assets/25375373/7b1b7293-03cd-4ef1-91d3-8f2efde0899a"/> </td>
    <td>
        
This AI will:
        
- 🤖 write digital pathology analyses for you
- 🔬 walk you through the code, step-by-step
- 🎓 be your teacher, as you embark on your digital pathology journey ❤️

More information [here](./ai-digital-pathology-assistant-v3) and usage examples [here](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/talk_to_pathml.ipynb)
  
</td>
</tr>
</table>


📖 **Official PathML Documentation**

View the official [PathML Documentation on readthedocs](https://pathml.readthedocs.io/en/latest/)

🔥 **Examples! Examples! Examples!**

[↴ Jump to the gallery of examples below](#3-examples)

<br>

<img src=https://raw.githubusercontent.com/Dana-Farber-AIOS/pathml/master/docs/source/_static/images/logo.png width="300"> 

<img src=https://raw.githubusercontent.com/Dana-Farber-AIOS/pathml/master/docs/source/_static/images/overview.png width="750">

# 1. Installation

`PathML` is an advanced tool for pathology image analysis. Below are simplified instructions to help you install PathML on your system. Whether you're a user or a developer, follow these steps to get started.

## 1.1 Prerequisites

We recommend using [Micromamba](https://mamba.readthedocs.io/en/latest/index.html) for managing your environments. We provide instructions on how to install PathML via Micromamba below. In addition, we also provide instructions on how to install via [Miniconda](https://docs.conda.io/en/latest/miniconda.html) should you have a license. 

#### Installation 

If you don't have Miniconda installed, you can download Miniconda [here](https://docs.conda.io/en/latest/miniconda.html).


#### Upating Micromamba

Make sure you have the recent version of Micromamba by using the following command:
```
micromamba update 
```

####  Updating Conda and Using libmamba (Optional)

**If you are using Micromamba, you can skip to the next [section](#Platform-Specific-External-Dependencies).** 

 We recommend that Anaconda/Microconda users complete the following steps to update your Conda version and use `libmamba` to resolve dependency conflicts. 

Recent versions of Conda have integrated `libmamba`, a faster dependency solver. To benefit from this improvement, first ensure your Conda is updated:

````
conda update -n base conda
````

Then, to install and set the new `libmamba` solver, run:

````
conda install -n base conda-libmamba-solver
conda config --set solver libmamba
````
*Note: these instructions are for Linux. Commands may be different for other platforms.*

#### Platform-Specific External Dependencies

For installation methods [1)](#2.1-Install-with-Micromamba-and-pip-(Recommended-for-Users)) and [2)](#2.2-Install-from-Source-(Recommended-for-Developers)), you will need to install the following platform-specific packages. 

* Linux: Install external dependencies with [Apt](https://ubuntu.com/server/docs/package-management):
````
sudo apt-get install openslide-tools g++ gcc libblas-dev liblapack-dev
````

* MacOS: Install external dependencies with [Brew](www.brew.sh):
````
brew install openslide
````

* Windows:

 1. Option A: Install with [vcpkg](https://vcpkg.io/en/):
````
vcpkg install openslide
````

 2. Option B: Using Pre-built OpenSlide Binaries (Alternative)
For Windows users, an alternative to using `vcpkg` is to download and use pre-built OpenSlide binaries. This method is recommended if you prefer a quicker setup.

  - Download the OpenSlide Windows binaries from the [OpenSlide Downloads](https://openslide.org/download/) page.
  - Extract the archive to your desired location, e.g., `C:\OpenSlide\`.


## 1.2 PathML Installation Methods

### 1.2.1 Install with Micromamba and pip (Recommended for Users)

#### Create and Activate Micromamba Environment and install openjdk
````
micromamba create -n pathml  'openjdk<=18.0' -c conda-forge python=3.9
micromamba activate pathml
````

#### Install `PathML` from PyPI
````
pip install pathml
````

### 1.2.2 Install with Anaconda and pip 

#### Create and Activate Conda Environment
````
conda create --name pathml python=3.9
conda activate pathml
````
#### Install OpenJDK 
````
conda install -c conda-forge 'openjdk<=18.0'
````

#### Install `PathML` from PyPI
````
pip install pathml
````

### 1.2.3 Install from Source (Recommended for Developers)

#### Clone repository
````
git clone https://github.com/Dana-Farber-AIOS/pathml.git
cd pathml
````

#### Create conda environment 

* Linux and Windows:

````
conda env create -f environment.yml
conda activate pathml
````
To use GPU acceleration for model training or other tasks, you must install CUDA. The default CUDA version in our environment file is 11.6. To install a different CUDA version, refer to the instructions [here](#CUDA)). 

* MacOS:

````
conda env create -f requirements/environment_mac.yml
conda activate pathml
````

#### Install `PathML` from source: 
````
pip install -e .
````

### 1.2.4 Use Docker Container

First, download or build the PathML Docker container:

![pathml-docker-installation](https://user-images.githubusercontent.com/25375373/191053363-477497a1-9804-48f3-91f9-767dc7f859ed.gif)

- Option A: download PathML container from Docker Hub
   ````
   docker pull pathml/pathml:latest
   ````
  Optionally specify a tag for a particular version, e.g. `docker pull pathml/pathml:2.0.2`. To view possible tags, 
  please refer to the [PathML DockerHub page](https://hub.docker.com/r/pathml/pathml).
  
- Option B: build docker container from source
   ````
   git clone https://github.com/Dana-Farber-AIOS/pathml.git
   cd pathml
   docker build -t pathml/pathml .
   ````

Then connect to the container:
````
docker run -it -p 8888:8888 pathml/pathml
````

The above command runs the container, which is configured to spin up a jupyter lab session and expose it on port 8888. 
The terminal should display a URL to the jupyter lab session starting with `http://127.0.0.1:8888/lab?token=<.....>`. 
Navigate to that page and you should connect to the jupyter lab session running on the container with the pathml 
environment fully configured. If a password is requested, copy the string of characters following the `token=` in the 
url.

Note that the docker container requires extra configurations to use with GPU.  
Note that these instructions assume that there are no other processes using port 8888.

Please refer to the `Docker run` [documentation](https://docs.docker.com/engine/reference/run/) for further instructions
on accessing the container, e.g. for mounting volumes to access files on a local machine from within the container.

### 1.2.5 Use Google Colab

To get PathML running in a Colab environment:

````
import os
!pip install openslide-python
!apt-get install openslide-tools
!apt-get install openjdk-17-jdk-headless -qq > /dev/null
os.environ["JAVA_HOME"] = "/usr/lib/jvm/java-17-openjdk-amd64"
!update-alternatives --set java /usr/lib/jvm/java-17-openjdk-amd64/bin/java
!java -version
!pip install pathml
````

*Thanks to all of our open-source collaborators for helping maintain these installation instructions!*  
*Please open an issue for any bugs or other problems during installation process.*

## 1.3. Import PathML

After you have installed all necessary dependencies and PathML itself, import it using the following command:

````
import pathml
````

For Windows users, insert the following code snippet at the beginning of your Python script or Jupyter notebook before importing PathML. This code sets up the DLL directory for OpenSlide, ensuring that the library is properly loaded:

```python

# The path can also be read from a config file, etc.
OPENSLIDE_PATH = r'c:\path\to\openslide-win64\bin'

import os
if hasattr(os, 'add_dll_directory'):
    # Windows-specific setup
    with os.add_dll_directory(OPENSLIDE_PATH):
        import openslide
else:
    # For other OSes, this step is not needed
    import openslide

# Now you can proceed with using PathML
import pathml
```
This code snippet ensures that the OpenSlide DLLs are correctly found by Python on Windows systems. Replace c:\path\to\openslide-win64\bin with the actual path where you extracted the OpenSlide binaries.

If you encounter any DLL load failures, verify that the OpenSlide `bin` directory is correctly added to your `PATH`.


## 1.4 CUDA

To use GPU acceleration for model training or other tasks, you must install CUDA. 
This guide should work, but for the most up-to-date instructions, refer to the [official PyTorch installation instructions](https://pytorch.org/get-started/locally/).

Check the version of CUDA:
````
nvidia-smi
````

Replace both instances of 'cu116' in `requirements/requirements_torch.txt` with the CUDA version you see. For example, for CUDA 11.7, 'cu116' becomes 'cu117'. 

Then create the environment:

````
conda env create -f environment.yml
conda activate pathml
````

After installing PyTorch, optionally verify successful PyTorch installation with CUDA support: 
````
python -c "import torch; print(torch.cuda.is_available())"
````

# 2. Using with Jupyter (optional)

Jupyter notebooks are a convenient way to work interactively. To use `PathML` in Jupyter notebooks: 

## 2.1 Set JAVA_HOME environment variable

PathML relies on Java to enable support for reading a wide range of file formats.
Before using `PathML` in Jupyter, you may need to manually set the `JAVA_HOME` environment variable 
specifying the path to Java. To do so:

1. Get the path to Java by running `echo $JAVA_HOME` in the terminal in your pathml conda environment (outside of Jupyter)
2. Set that path as the `JAVA_HOME` environment variable in Jupyter:
    ````
    import os
    os.environ["JAVA_HOME"] = "/opt/conda/envs/pathml" # change path as needed
    ````

## 2.2 Register environment as an IPython kernel
````
conda activate pathml
conda install ipykernel
python -m ipykernel install --user --name=pathml
````
This makes the pathml environment available as a kernel in jupyter lab or notebook.

# 3. Examples

Now that you are all set with ``PathML`` installation, let's get started with some analyses you can easily replicate:

<table style="border: 0px !important;">
    <tr>
    <td> 
        
1. [Load over 160+ different types of pathology images using PathML](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/loading_images_vignette.ipynb)
2. [H&E Stain Deconvolution and Color Normalization](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/stain_normalization.ipynb)
3. [Brightfield imaging pipeline: load an image, preprocess it on a local cluster, and get it read for machine learning analyses in PyTorch](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/workflow_HE_vignette.ipynb)
4. [Multiparametric Imaging: Quickstart & single-cell quantification](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/multiplex_if.ipynb)
5. [Multiparametric Imaging: CODEX & nuclei quantization](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/codex.ipynb)
6. [Train HoVer-Net model to perform nucleus detection and classification, using data from PanNuke dataset](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/train_hovernet.ipynb)
7. [Gallery of PathML preprocessing and transformations](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/pathml_gallery.ipynb)
8. [Use the new Graph API to construct cell and tissue graphs from pathology images](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/construct_graphs.ipynb)
9. [Train HACTNet model to perform cancer sub-typing using graphs constructed from the BRACS dataset](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/train_hactnet.ipynb)
10. [Perform reconstruction of tiles obtained from pathology images using Tile Stitching](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/tile_stitching.ipynb)
11. [Create an ONNX model in HaloAI or similar software, export it, and run it at scale using PathML](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/InferenceOnnx_tutorial.ipynb)
12. [Step-by-step process used to analyze the Whole Slide Images (WSIs) of Non-Small Cell Lung Cancer (NSCLC) samples as published in the Journal of Clinical Oncology](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/Graph_Analysis_NSCLC.ipynb)
13. [Talk to the PathML Digital Pathology Assistant](https://github.com/Dana-Farber-AIOS/pathml/blob/master/examples/talk_to_pathml.ipynb)

</td>                                                                                                                             
        <td>
<img src="https://github.com/Dana-Farber-AIOS/pathml/assets/25375373/502c9e69-e988-4d61-b50f-0d6bfc8af251" width="1000px" />

   </td>
</tr>
</table>

# 4. Citing & known uses

If you use ``PathML`` please cite:

- [**M. Omar et al., "Antibody-Based Multiplex Image Analysis: Standard Analytical Workflows and Artificial Intelligence Tools for Pathologists." Laboratory Investigation, 2025.**](https://doi.org/10.1016/j.labinv.2025.104220)

So far, **PathML** was referenced in 40+ manuscripts:

-   [Y. Han et al. **npj Precision Oncology**, 2025](https://www.nature.com/articles/s41698-025-01056-8)
-   [L. Heumos et al. **Nature Medicine**, 2024](https://www.nature.com/articles/s41591-024-03214-0)
-   [M. Omar et al. **Lancet Digital Health**, 2024](https://www.thelancet.com/journals/landig/article/PIIS2589-7500(24)00114-6/fulltext)
-   [H. Pakula et al. **Nature Communications**, 2024](https://www.nature.com/articles/s41467-023-44210-1)
-   [B. Ricciuti et al. **Journal of Clinical Oncology**, 2024](https://ascopubs.org/doi/full/10.1200/JCO.23.00580)
-   [DT. Hoang et al. **Nature Cancer**, 2024](https://www.nature.com/articles/s43018-024-00793-2)
-   [A. Song et al. **Nature Reviews Bioengineering**, 2023](https://www.nature.com/articles/s44222-023-00096-8)
-   [I. Virshup et al. **Nature Bioengineering**, 2023](https://www.nature.com/articles/s41587-023-01733-8)
-   [A. Karargyris et al. **Nature Machine Intelligence**, 2023](https://www.nature.com/articles/s42256-023-00652-2)
-   [S. Pati et al. **Nature Communications Engineering**, 2023](https://www.nature.com/articles/s44172-023-00066-3)
-   [C. Gorman et al. **Nature Communications**, 2023](https://www.nature.com/articles/s41467-023-37224-2)
-   [J. Nyman et al. **Cell Reports Medicine**, 2023](https://doi.org/10.1016/j.xcrm.2023.101189)
-   [A. Shmatko et al. **Nature Cancer**, 2022](https://www.nature.com/articles/s43018-022-00436-4)
-   [J. Pocock et al. **Nature Communications Medicine**, 2022](https://www.nature.com/articles/s43856-022-00186-5)
-   [S. Orsulic et al. **Frontiers in Oncology**, 2022](https://www.frontiersin.org/articles/10.3389/fonc.2022.924945/full)
-   [J. Linares et al. **Molecular Cell**, 2021](https://doi.org/10.1016/j.molcel.2021.08.039)
-   the list continues [**here** **🔗**](https://scholar.google.com/scholar?oi=bibs&hl=en&cites=1157052756975292108)

# 5. Users

<table style="border: 0px !important;"><tr><td>This is where in the world our most enthusiastic supporters are located:
   <br/><br/>
<img src="https://github.com/user-attachments/assets/18fdaf1c-5ee0-48db-b0d4-99698184c93e" width="722px">
   </td><td>   
and this is where they work:
   <br/><br/>
<img src="https://github.com/user-attachments/assets/0ce73bb5-a722-4dc8-8846-824757e45f0c" width="400px">
</td>                                                                                                                             
</tr>
</table>

Source: https://ossinsight.io/analyze/Dana-Farber-AIOS/pathml#people

# 6. Contributing

``PathML`` is an open source project. Consider contributing to benefit the entire community!

There are many ways to contribute to `PathML`, including:

* Submitting bug reports
* Submitting feature requests
* Writing documentation and examples
* Fixing bugs
* Writing code for new features
* Sharing workflows
* Sharing trained model parameters
* Sharing ``PathML`` with colleagues, students, etc.

See [contributing](https://github.com/Dana-Farber-AIOS/pathml/blob/master/CONTRIBUTING.rst) for more details.


# 7. License

The GNU GPL v2 version of PathML is made available via Open Source licensing. 
The user is free to use, modify, and distribute under the terms of the GNU General Public License version 2.

Commercial license options are available also.

# 8. Contact

Questions? Comments? Suggestions? Get in touch!

[innovation@dfci.harvard.edu](mailto:innovation@dfci.harvard.edu)

<img src=https://raw.githubusercontent.com/Dana-Farber-AIOS/pathml/master/docs/source/_static/images/dfci_cornell_joint_logos.png width="750">