libvips / node-vips

Experiment with a libvips binding for node using ffi

libvips: an image processing library

Introduction

libvips is a demand-driven, horizontally threaded image processing library. Compared to similar libraries, libvips runs quickly and uses little memory. libvips is licensed under the LGPL 2.1+.

It has around 300 operations covering arithmetic, histograms, convolution, morphological operations, frequency filtering, colour, resampling, statistics and others. It supports a large range of numeric types, from 8-bit int to 128-bit complex. Images can have any number of bands. It supports a good range of image formats, including JPEG, JPEG2000, 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, letting it work with formats like DICOM.

It comes with bindings for C, C++, and the command-line. Full bindings are available for :

Language	Binding
Ruby	ruby-vips
Python	pyvips
PHP	php-vips
C# / .NET	NetVips
Go	govips
Lua	lua-vips
Crystal	crystal-vips
Elixir	vix

libvips is used as an image processing engine by:

sharp (on node.js)
imgproxy
bimg
sharp for Go
Ruby on Rails
carrierwave-vips
mediawiki
PhotoFlow

and others. The official libvips GUI is nip2, a strange combination of a spreadsheet and a photo editor.

Install

There are packages for most Unix-like operating systems, including macOS. Check your package manager.

There are binaries for Windows in releases.

The libvips website has detailed install notes.

Building from source

libvips uses the Meson build system, version 0.56 or later. Meson can use ninja, Visual Studio or XCode as a backend, so you'll also need one of them.

libvips must have build-essential, pkg-config, libglib2.0-dev, libexpat1-dev. See the Dependencies section below for a full list of the libvips optional dependencies.

There are basic bash completions in completions/, see the README in there.

Cheatsheet

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

Check the output of meson setup carefully and make sure it found everything you wanted it to find. Add arguments to meson setup to change the build configuration.

• Add flags like -Dnsgif=false to turn libvips options on and off, see meson_options.txt for a list of all the build options libvips supports.

• Add flags like -Dmagick=disabled to turn libvips dependencies on and off, see meson_options.txt and the list below for a summary of all the libvips dependencies.

• You might need to add --libdir lib on Debian if you don't want the arch name in the library path.

• Add --default-library static for a static build.

• Use eg. CC=clang CXX=clang++ meson setup ... to change compiler.

• You can have many build-dir, pick whatever names you like, for example one for release and one for debug.

There's a more comprehensive test suite you can run once libvips has been installed. Use pytest in the libvips base directory.

Optional dependencies

If suitable versions are found, libvips will add support for the following libraries automatically. Packages are generally found with pkg-config, so make sure that is working.

libjpeg

Anything that is compatible with the IJG JPEG library. Use mozjpeg if you can. Another option is libjpeg-turbo.

libexif

If available, libvips adds support for EXIF metadata in JPEG files.

librsvg

The usual SVG loader. If this is not present, vips will try to load SVGs via imagemagick instead.

PDFium

If present, libvips will attempt to load PDFs with PDFium. Download the prebuilt pdfium binary from:

https://github.com/bblanchon/pdfium-binaries

Untar to the libvips install prefix, for example:

cd ~/vips
tar xf ~/pdfium-linux.tgz

Create a pdfium.pc like this (update the version number):

VIPSHOME=/home/john/vips
cat > $VIPSHOME/lib/pkgconfig/pdfium.pc << EOF
     prefix=$VIPSHOME
     exec_prefix=\${prefix}
     libdir=\${exec_prefix}/lib
     includedir=\${prefix}/include
     Name: pdfium
     Description: pdfium
     Version: 4290
     Requires:
     Libs: -L\${libdir} -lpdfium
     Cflags: -I\${includedir}
EOF

If PDFium is not detected, libvips will look for poppler-glib instead.

poppler-glib

The Poppler PDF renderer, with a glib API. If this is not present, vips will try to load PDFs via imagemagick.

cgif

If available, libvips will save GIFs with cgif. If this is not present, vips will try to save gifs via imagemagick instead.

libarchive

If available, libvips adds support for creating image pyramids with dzsave.

libtiff

The TIFF library. It needs to be built with support for JPEG and ZIP compression. 3.4b037 and later are known to be OK.

fftw3

If libvips finds this library, it uses it for fourier transforms.

lcms2

If present, vips_icc_import(), vips_icc_export() and vips_icc_transform() can be used to manipulate images with ICC profiles.

libspng

If present, libvips will load and save PNG files using libspng. If not, it will look for the standard libpng package.

libimagequant, quantizr

If one of these quantisation packages is present, libvips can write 8-bit palette-ised PNGs and GIFs.

ImageMagick, or optionally GraphicsMagick

If available, libvips adds support for loading and saving all libMagick-supported image file types. You can enable and disable load and save separately.

Imagemagick 6.9+ needs to have been built with --with-modules. Most packaged IMs are, I think.

If you are going to be using libvips with untrusted images, perhaps in a web server, for example, you should consider the security implications of enabling a package with such a large attack surface.

pangocairo

If available, libvips adds support for text rendering. You need the package pangocairo in pkg-config --list-all.

highway

If present, libvips will accelerate some operations with SIMD. If not, it will look for the orc-0.4 package.

matio

If available, vips can load images from Matlab save files.

cfitsio

If available, vips can load FITS images.

libwebp

If available, vips can load and save WebP images.

libniftiio

If available, vips can load and save NIfTI images.

OpenEXR

If available, libvips will directly read (but not write, sadly) OpenEXR images.

OpenJPEG

If available, libvips will read and write JPEG2000 images.

libjxl

If available, libvips will read and write JPEG-XL images.

OpenSlide

If available, libvips can load OpenSlide-supported virtual slide files: Aperio, Hamamatsu, Leica, MIRAX, Sakura, Trestle, and Ventana.

libheif

If available, libvips can load and save HEIC and AVIF images. Your libheif (in turn) needs to be built with the correct decoders and encoders. You can check with eg.:

$ heif-convert --list-decoders
HEIC decoders:
- libde265 = libde265 HEVC decoder, version 1.0.9
AVIF decoders:
- dav1d = dav1d v6.6.0
- aom = AOMedia Project AV1 Decoder v3.5.0
$ heif-enc --list-encoders
HEIC encoders:
- x265 = x265 HEVC encoder (3.5+1-f0c1022b6) [default]
AVIF encoders:
- aom = AOMedia Project AV1 Encoder v3.5.0 [default]
- svt = SVT-AV1 encoder v1.1.0
- rav1e = Rav1e encoder

Contributors

Code Contributors

This project exists thanks to all the people who contribute.

Organizations

We've had generous financial support from our sponsors. Thank you very much!

node-vips's Issues

Writing 50mb output file for 10mb input file after shrink operation

Hi!
libvips has every possible thing I could possibly need for a very involving project and is super fast!
I'm trying to use it from node because there're a few things sharp doesn't do that libvips supports.

The following script produced an image that was 5 times the input size i.e. ~10.2mb to ~56.8mb

var vips = require('vips-ffi');
var image = vips.Image.newFromFile('patrick-hendry-547014-unsplash.jpg');
image.shrink(50, 50)
image.writeToFile('testc.png')

How would I resize an image?

Investigate fastcall as possible replacement for node-ffi

I came across fastcall, I thought let's open an issue to track this.

There is a a popular dynamic binding library for Node.js:
node-ffi. Then why we need another one could ask? For performance! There is a good 20x-40x
function call performance overhead when using node-ffi compared to hand made C++ native module, which is unacceptable in most cases (see the benchmarks).

fastcall has an almost 100% node-ffi compatible interface, so it could work as a drop-in replacement of node-ffi.

(I can't work on this before February 2019, since I'm currently busy with my internship.)

TODO

Things that need doing before we could declare 1.0, in no order:

• Documentation
• Sort out naming conventions: we should probably switch to newFromFile(), for example
• what about .bandsplit() and .bandjoin()? Should they be .bandSplit() and .bandJoin()?
• Fix module structure, hide internal things
• Have something to generate convenience members for Image, eg. Image.black should be generated automatically.
• Need convenience functions like Image.prototype.bandsplit
• Enum expansions, eg. Image.prototype.sin
• Need to handle the libvips error buffer
• Fix up exceptions
• More arithmetic wrappers need doing by hand, eg. see Image.prototype.add
• Load/save unformatted memory areas, eg. a Buffer holding a uint8 pixel array
• Load/save formatted memory areas, eg. a string holding a PNG
• Need to wrap VipsInterpolate
• Some examples
• Benchmarks
• Make it "just work" on Windows (it works right now, but you have to change the library names, see the FIXME notes)
• We open the libraries several times. It would be better to open once and share the handles. We could have code to use the Windows library names in just one place then as well.
• We seem to leak some buffers in example/thumb.js in memory mode, investigate
• Travis integration
• Add vips.call.async

Please add more!