imageio - a Python library for reading and writing image data


Imageio is a Python library that provides an easy interface to read and write a wide range of image data, including animated images, video, volumetric data, and scientific formats. It is cross-platform, runs on Python 2.x and 3.x, and is easy to install.

Example

Here's a minimal example of how to use imageio. See the docs for more examples.
>>> import imageio
>>> im = imageio.imread('chelsea.png')
>>> im.shape  # im is a numpy array
(300, 451, 3)
>>> imageio.imwrite('chelsea-gray.jpg', im[:, :, 0])

API in a nutshell

As a user, you just have to remember a handfull of functions:

Features

Details

Imageio has a relatively simple core that provides a common interface to different file formats. This core takes care of reading from different sources (like http), and exposes a simple API for the plugins to access the raw data. All file formats are implemented in plugins. Additional plugins can easily be registered.

Some plugins rely on external libraries (e.g. freeimage). These are automatically downloaded when needed and cached in your appdata directory. This keeps imageio light and scalable.

We plan to provide a wide range of image formats. Also scientific formats. Any help in implementing more formats is very welcome!

The codebase adheres to (a subset of) the PEP8 style guides. We strive for maximum test coverage (100% for the core, >95% for each plugin).

Origin and outlook

Imageio was based out of the frustration that many libraries that needed to read or write image data produced their own functionality for IO. PIL did not meet the needs very well, and libraries like scikit-image need to be able to deal with scientific formats. I felt there was a need for a good image io library, which is an easy dependency, easy to maintain, and scalable to exotic file formats.

Imageio started out with the FreeImage plugin of the scikit-image project, through which it was able to support a lot of common formats. We created a simple but powerful core, a clean user API, and a proper plugin system.

The purpose of imageio is to support reading and writing of image data. We're not processing images, you should use scikit-image for that. Imageio should be easy to install and be lightweight. Imageio's plugin system makes it possible to scale the number of supported formats and still keep a low footprint.

It is impossible for one person to implement and maintain a wide variety of formats. My hope is to form a group of developers, who each maintain one or more plugins. In that way, the burder of each developer is low, and together we can make imageio into a really useful library!