In Operation
qoiconv lets us convert existing PNG files to the QOI format, as well as convert them back. The syntax is simple.
From testing a range of image files, we saw image compression times over 30 times faster than the Libpng library. The compression QOI provides is, on average, about the same as that of PNG, but it does depend on the image data. We did see files significantly larger with QOI.
There are only a few native image viewers that support the .qoi file. On the first page of this articles we installed qoiview and tev.
Here’s a high resolution image displayed with qoiview.
For a more featureful image viewer that supports QOI, check out tev.
Summary
QOI is pretty feature-complete. It’s not designed to be a complex format, but it combines several simple ideas. QOI can also be compressed with general compression algorithms.
With time, hopefully more software will support the QOI format. But it’s already useful for compressing and archiving images.
qoiconv is written in C, but there are implementations available for other languages including Go, Rust, Python, Java, Dart, and Lua.
For more command-line image compression tools, explore our roundup. All free and open source goodness.
Website: qoiformat.org
Support: GitHub Code Repository
Developer: Dominic Szablewski
License: MIT License
QOI is written in C. Learn C with our recommended free books and free tutorials.
Pages in this article:
Page 1 – Introduction and Installation
Page 2 – In Operation and Summary