libvips: An Image Processing Library

What It Is

libvips is a library for processing images — resizing, cropping, filtering, converting formats, and many other operations. Its key design trait is that it's demand-driven and horizontally threaded: it only does the work you actually ask for, and it splits that work across multiple CPU threads. The README claims this makes it fast and memory-efficient compared to similar libraries.

It's open source, licensed under LGPL-2.1-or-later.

What It Can Do

~300 operations covering arithmetic, histograms, convolution, morphological operations, frequency filtering, colour, resampling, statistics, and more.
Wide numeric range: from 8-bit integers up to 128-bit complex numbers.
Any number of bands per image (e.g., grayscale, RGB, RGBA, or more).
Many image formats: JPEG, JPEG 2000, JPEG XL, TIFF, PNG, WebP, HEIC, AVIF, FITS, Matlab, OpenEXR, PDF, SVG, HDR, PPM/PGM/PFM, CSV, GIF, Analyze, NIfTI, DeepZoom, and OpenSlide. It can also load images via ImageMagick or GraphicsMagick, which extends support to formats like DICOM.

Language Bindings

It ships with built-in bindings for C, C++, and a command-line interface. Full community bindings exist for:

Ruby (ruby-vips)
Python (pyvips)
PHP (php-vips)
C# / .NET (NetVips)
Go (vips-gen)
Lua (lua-vips)
Crystal (crystal-vips)
Elixir (vix)
Java (vips-ffm)
Nim (libvips-nim)
Rust (vips-rs)

Who Uses It

Notable projects that use libvips as their image processing engine:

Mastodon (social network)
sharp (Node.js image library)
imgproxy
wsrv.nl
bimg
Ruby on Rails (Active Storage)
CarrierWave
MediaWiki

The official GUI for libvips is nip4, described as "a strange combination of a spreadsheet and a photo editor."

Installation

Unix-like systems (including macOS): packages are available via most package managers.
Windows: prebuilt binaries are provided in the project's GitHub releases.
Detailed install notes are on the libvips website.

Building from Source

Requirements:

Meson build system (version 0.56 or later)
A backend for Meson: ninja, Visual Studio, or XCode
Core dependencies: build-essential, pkg-config, libglib2.0-dev, libexpat1-dev

Basic build steps:

cd libvips-x.y.z
meson setup build --prefix /my/install/prefix
cd build
meson compile
meson test
meson install

You can toggle features and dependencies with flags like -Dnsgif=false or -Dmagick=disabled (see meson_options.txt). After installation, a more comprehensive test suite can be run with pytest.

Optional Dependencies

libvips automatically enables support for libraries it finds on your system. Key ones include:

libjpeg (or mozjpeg / libjpeg-turbo) — JPEG
libultrahdr — UltraHDR images
libexif — EXIF metadata in JPEGs
librsvg — SVG loading (falls back to ImageMagick)
libraw — camera RAW loading (falls back to ImageMagick)
PDFium or poppler-glib — PDF loading (falls back to ImageMagick)
cgif — GIF saving (falls back to ImageMagick)
libarchive — image pyramids via dzsave
libtiff — TIFF
fftw3 — Fourier transforms
lcms2 — ICC profile manipulation
libpng — PNG (falls back to spng)
libimagequant or quantizr — 8-bit palette-ised PNG/GIF writing
ImageMagick or GraphicsMagick — broad format support (the README warns about security implications of enabling this for untrusted images)
pangocairo — text rendering
highway — SIMD acceleration (falls back to orc-0.4)
matio — Matlab files
cfitsio — FITS images
libwebp — WebP
libniftiio — NIfTI images
OpenEXR — reading OpenEXR (not writing)
OpenJPEG — JPEG 2000
libjxl — JPEG XL
OpenSlide — virtual slide formats (Aperio, Hamamatsu, Leica, MIRAX, Sakura, Trestle, Ventana)
libheif — HEIC and AVIF (requires libheif built with appropriate codecs)

Summary

libvips is a mature, widely adopted image processing library that prioritizes speed and low memory usage through demand-driven, threaded execution. It supports a vast range of formats and operations, has bindings for most major languages, and is used in production by well-known projects. It's easy to install via package managers, and building from source is straightforward with Meson.

libvips/libvips