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anatomical segmentation algorithm

Project description

Cellpose cellpose

A generalist algorithm for cell and nucleus segmentation.

This code was written by Carsen Stringer and Marius Pachitariu. To learn about Cellpose, read the paper or watch the talk. For support, please open an issue.

If you want to improve Cellpose for yourself and for everyone else, please consider contributing manual segmentations for a few of your images via the built-in GUI interface (see instructions below).

Run cellpose without local installation

You can quickly try out Cellpose on the website first (some features disabled).

You can also run Cellpose in google colab with a GPU -> Open In Colab. This is recommended if you have issues with MKL or run speed on your local computer (and are running 3D volumes). Colab does not allow you to run the GUI, but you can save *_seg.npy files in colab that you can download and open in the GUI.

Detailed documentation at

System requirements

Linux, Windows and Mac OS are supported for running the code. For running the graphical interface you will need a Mac OS later than Yosemite. At least 8GB of RAM is required to run the software. 16GB-32GB may be required for larger images and 3D volumes. The software has been heavily tested on Windows 10 and Ubuntu 18.04 and less well-tested on Mac OS. Please open an issue if you have problems with installation.


This process should take less than 5 minutes.

(Option 1) Standard install in base environment

  1. Install an Anaconda distribution of Python -- Choose Python 3.7 and your operating system. Note you might need to use an anaconda prompt if you did not add anaconda to the path.
  2. From your base environment in an anaconda prompt/command prompt, run
pip install cellpose[gui]

If you want to install without the GUI dependencies, run pip install cellpose.

(Option 2) Install in a new environment

Alternatively you can use the included environment file (if you'd like a cellpose-specific environment). This environment file includes all the dependencies for using the GUI. Using the environment file is recommended if you have problems with option 1. Please follow these instructions:

  1. Download the environment.yml file from the repository. You can do this by cloning the repository, or copy-pasting the text from the file into a text document on your local computer.
  2. Open an anaconda prompt / command prompt with conda for python 3 in the path
  3. Change directories to where the environment.yml is and run conda env create -f environment.yml
  4. To activate this new environment, run conda activate cellpose
  5. You should see (cellpose) on the left side of the terminal line. Now run python -m cellpose and you're all set.

To upgrade cellpose (package here), run the following in the environment:

pip install cellpose --upgrade

If you have an older cellpose environment you can remove it with conda env remove -n cellpose before creating a new one.

Note you will always have to run conda activate cellpose before you run cellpose. If you want to run jupyter notebooks in this environment, then also conda install jupyter.

Common issues

If you receive the error: Illegal instruction (core dumped), then likely mxnet does not recognize your MKL version. Please uninstall and reinstall mxnet without mkl:

pip uninstall mxnet-mkl
pip uninstall mxnet
pip install mxnet==1.4.0

MAC OS ISSUE: You may have an issue on Mac with the latest opencv-python library (package name cv2). Downgrade it with the command

pip install opencv-python==

If you receive the error: No module named PyQt5.sip, then try uninstalling and reinstalling pyqt5

pip uninstall pyqt5 pyqt5-tools
pip install pyqt5 pyqt5-tools pyqt5.sip

If you receive an error associated with matplotlib, try upgrading it:

pip install matplotlib --upgrade

If you receive the error: ImportError: _arpack DLL load failed, then try uninstalling and reinstalling scipy

pip uninstall scipy
pip install scipy

If you are having issues with the graphical interface, make sure you have python 3.7 and not python 3.8 installed.

CUDA version

If you plan on running many images, you may want to install a GPU version of mxnet. I recommend using CUDA 10.0 or greater. Follow the instructions here.

Before installing the GPU version, remove the CPU version:

pip uninstall mxnet-mkl
pip uninstall mxnet

When upgrading cellpose, you will want to ignore dependencies (so that mxnet-mkl does not install):

pip install --no-deps cellpose --upgrade

Installation of github version

Follow steps from above to install the dependencies. In the github repository, run pip install -e . and the github version will be installed. If you want to go back to the pip version of cellpose, then say pip install cellpose.

Running cellpose

The quickest way to start is to open the GUI from a command line terminal. You might need to open an anaconda prompt if you did not add anaconda to the path:

python -m cellpose

The first time cellpose runs it downloads the latest available trained model weights from the website.

You can now drag and drop any images (*.tif, *.png, *.jpg, *.gif) into the GUI and run Cellpose, and/or manually segment them. When the GUI is processing, you will see the progress bar fill up and during this time you cannot click on anything in the GUI. For more information about what the GUI is doing you can look at the terminal/prompt you opened the GUI with. For example data, see website or this google drive folder. For best accuracy and runtime performance, resize images so cells are less than 100 pixels across.

Step-by-step demo

  1. Download the google drive folder and unzip it. These are a subset of the test images from the paper.
  2. Start the GUI with python -m cellpose.
  3. Drag an image from the folder into the GUI.
  4. Set the model (in demo all are cyto) and the channel you want to segment (in demo all are green). Optionally set the second channel if you are segmenting cyto and have an available nucleus channel.
  5. Click the calibrate button to estimate the size of the objects in the image. Alternatively you can set the cell diameter by hand and press ENTER. You will see the size you set as a red disk at the bottom left of the image.
  6. Click the run segmentation button. If MASKS ON is checked, you should see masks drawn on the image.
  7. Now you can click the LEFT/RIGHT arrow keys to move through the folder and segment another image.

On the demo images each of these steps should run in less than a few seconds on a standard laptop or desktop (with mkl working).

3D segmentation

For multi-channel, multi-Z tiff's, the expected format is Z x channels x Ly x Lx.

Contributing training data

We are very excited about receiving community contributions to the training data and re-training the cytoplasm model to make it better. Please follow these guidelines:

  1. Run cellpose on your data to see how well it does. Try varying the diameter, which can change results a little.
  2. If there are relatively few mistakes, it won't help much to contribute labelled data.
  3. If there are consistent mistakes, your data is likely very different from anything in the training set, and you should expect major improvements from contributing even just a few manually segmented images.
  4. For images that you contribute, the cells should be at least 10 pixels in diameter, and there should be at least several dozens of cells per image, ideally ~100. If your images are too small, consider combining multiple images into a single big one and then manually segmenting that. If they are too big, consider splitting them into smaller crops.
  5. For the manual segmentation, please try to outline the boundaries of the cell, so that everything (membrane, cytoplasm, nucleus) is inside the boundaries. Do not just outline the cytoplasm and exclude the membrane, because that would be inconsistent with our own labelling and we wouldn't be able to use that.
  6. Do not use the results of the algorithm in any way to do contributed manual segmentations. This can reinforce a vicious circle of mistakes, and compromise the dataset for further algorithm development.

If you are having problems with the nucleus model, please open an issue before contributing data. Nucleus images are generally much less diverse, and we think the current training dataset already covers a very large set of modalities.

Using the GUI

The GUI serves two main functions:

  1. Running the segmentation algorithm.
  2. Manually labelling data.

Main GUI mouse controls (works in all views):

  • Pan = left-click + drag
  • Zoom = scroll wheel
  • Full view = double left-click
  • Select mask = left-click on mask
  • Delete mask = Ctrl + left-click
  • Start draw mask = right-click
  • End draw mask = right-click, or return to circle at beginning

Overlaps in masks are NOT allowed. If you draw a mask on top of another mask, it is cropped so that it doesn't overlap with the old mask. Masks in 2D should be single strokes (if single_stroke is checked).

If you want to draw masks in 3D, then you can turn single_stroke option off and draw a stroke on each plane with the cell and then press ENTER. 3D labelling will fill in unlabelled z-planes so that you do not have to as densely label.

!NOTE!: The GUI automatically saves after you draw a mask but NOT after segmentation and NOT after 3D mask drawing (too slow). Save in the file menu or with Ctrl+S. The output file is in the same folder as the loaded image with _seg.npy appended.

Keyboard shortcuts Description
CTRL+H help
CTRL+Z undo previously drawn mask/stroke
CTRL+0 clear all masks
CTRL+L load image (can alternatively drag and drop image)
CTRL+S SAVE MASKS IN IMAGE to _seg.npy file
CTRL+P load _seg.npy file (note: it will load automatically with image if it exists)
CTRL+M load masks file (must be same size as image with 0 for NO mask, and 1,2,3... for masks)
CTRL+N load numpy stack (NOT WORKING ATM)
A/D or LEFT/RIGHT cycle through images in current directory
W/S or UP/DOWN change color (RGB/gray/red/green/blue)
PAGE-UP / PAGE-DOWN change to flows and cell prob views (if segmentation computed)
, / . increase / decrease brush size for drawing masks
X turn masks ON or OFF
Z toggle outlines ON or OFF
C cycle through labels for image type (saved to _seg.npy)

Segmentation options

SIZE: you can manually enter the approximate diameter for your cells, or press "calibrate" to let the model estimate it. The size is represented by a disk at the bottom of the view window (can turn this disk off by unchecking "scale disk on").

use GPU: if you have installed the cuda version of mxnet, then you can activate this, but it won't give huge speedups when running single images in the GUI.

MODEL: there is a cytoplasm model and a nuclei model, choose what you want to segment

CHAN TO SEG: this is the channel in which the cytoplasm or nuclei exist

CHAN2 (OPT): if cytoplasm model is chosen, then choose the nuclear channel for this option

In a notebook

See run_cellpose.ipynb.

From the command line

Run python -m cellpose and specify parameters as below. For instance to run on a folder with images where cytoplasm is green and nucleus is blue and save the output as a png:

python -m cellpose --dir ~/images_cyto/test/ --pretrained_model cyto --chan 2 --chan2 3 --save_png

You can specify the diameter for all the images or set to 0 if you want the algorithm to estimate it on an image by image basis. Here is how to run on nuclear data (grayscale) where the diameter is automatically estimated:

python -m cellpose --dir ~/images_nuclei/test/ --pretrained_model nuclei --diameter 0. --save_png

See the docs for more info.


See the docs for info.


cellpose relies on the following excellent packages (which are automatically installed with conda/pip if missing):

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