napari: A Multi-Dimensional Image Viewer for Python

napari is a community-built, Python-based, open-source tool. It’s designed for browsing, annotating, and analyzing large multi-dimensional images — providing point-and-click access to a growing ecosystem of image analysis plugins for scientists to use in their daily work. napari was designed to help Python practitioners as well as biologists and other scientists who want to access Python’s enormous scientific ecosystem, but may not have prior coding experience.

As an open-source tool, napari is built on inclusive, community-driven, and collaborative values and aims to serve scientific applications focused on visualization with simple, readable implementations. Researchers used napari to view SARS-CoV-2 virus particles after first converting the images to Zarr  — an open source tool funded by CZI’s Essential Open Source Software for Science program.   

napari supports large datasets and has six main distinct layer types that each correspond to a different data type, visualization, and interactivity. Users can add multiple layers of different types into the viewer and then work to adjust their properties, including performing manual annotations by painting labels or drawing polygons. All layer types support n-dimensional data, and the viewer allows users to quickly browse and visualize either 2D or 3D slices of these data.

The napari hub is a CZI project, built and managed to support the napari community. Individuals may use the existing ecosystem of napari plugins and build new plugins to meet the needs of scientists. This tool allows users to find community-built plugins that solve their analysis needs. Learn more about CZI grantees building plugins for napari. CZI also supports napari by funding the project and matching grants from other funders, with the goal of building a stronger coalition of partners to set up the project for long-term success.

Read more about the genesis and development of napari from CZI Imaging Software Fellow and napari co-founder Juan Nuñez-Iglesias, and read more about napari in Nature.