libvips/README.md

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libvips : an image processing library

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libvips is a 2D 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, convolutions, morphological operations, frequency filtering, colour, resampling, statistics and others. It supports a large range of numeric formats, from 8-bit int to 128-bit complex. It supports a good range of image formats, including JPEG, TIFF, PNG, WebP, FITS, Matlab, OpenEXR, PDF, SVG, HDR, PPM, CSV, GIF, Analyze, DeepZoom, and OpenSlide. It can also load images via ImageMagick or GraphicsMagick.

It has APIs for C and C++ and comes with a Python binding and a command-line interface. Bindings are available for Ruby, PHP, Go, JavaScript and others. There is full documentation. There are several GUIs as well, see the VIPS website.

There are packages for most unix-like operating systems and binaries for Windows and OS X.

Building libvips from a source tarball

We keep pre-baked tarballs of releases on the vips website:

https://github.com/jcupitt/libvips/releases

Untar, then in the libvips directory you should just be able to do:

$ ./configure

Check the summary at the end of configure carefully. libvips must have build-essential, pkg-config, glib2.0-dev, libexpat1-dev.

For the vips8 Python binding, you must also have gobject-introspection, python-gi-dev, and libgirepository1.0-dev.

You'll need the dev packages for the file format support you want. For basic jpeg and tiff support, you'll need libtiff5-dev, libjpeg-turbo8-dev, and libgsf-1-dev. See the Dependencies section below for a full list of the things that libvips can be configured to use.

Once configure is looking OK, compile and install with the usual:

$ make
$ sudo make install

By default this will install files to /usr/local.

We have detailed guides on the wiki for building on Windows and building on OS X.

Building libvips from git

Checkout the latest sources with:

$ git clone git://github.com/jcupitt/libvips.git

Building from git needs more packages, you'll need at least swig, gtk-doc and gobject-introspection, see the dependencies section below. For example:

$ brew install gtk-doc swig

Then build the build system with:

$ ./autogen.sh

Debug build:

$ CFLAGS="-g -Wall" CXXFLAGS="-g -Wall" \
	./configure --prefix=/home/john/vips --enable-debug
$ make
$ make install

Leak check:

$ export G_DEBUG=gc-friendly
$ valgrind --suppressions=libvips.supp \
	--leak-check=yes \
	vips ... > vips-vg.log 2>&1

Memory error debug:

$ valgrind --vgdb=yes --vgdb-error=0 vips  ...

valgrind threading check:

$ valgrind --tool=helgrind vips ... > vips-vg.log 2>&1

Clang build:

$ CC=clang CXX=clang++ ./configure --prefix=/home/john/vips

Clang static analysis:

$ scan-build ./configure --disable-introspection --disable-debug
$ scan-build -o scan -v make 
$ scan-view scan/2013-11-22-2

Clang dynamic analysis:

$ FLAGS="-O1 -g -fsanitize=address"
$ FLAGS="$FLAGS -fno-omit-frame-pointer -fno-optimize-sibling-calls"
$ CC=clang CXX=clang++ LD=clang \
	CFLAGS="$FLAGS" CXXFLAGS="$FLAGS" LDFLAGS=-fsanitize=address \
	./configure --prefix=/home/john/vips 

$ FLAGS="-O1 -g -fsanitize=thread"
$ FLAGS="$FLAGS -fPIC"
$ FLAGS="$FLAGS -fno-omit-frame-pointer -fno-optimize-sibling-calls"
$ CC=clang CXX=clang++ LD=clang \
	CFLAGS="$FLAGS" CXXFLAGS="$FLAGS" \
	LDFLAGS="-fsanitize=thread -fPIC" \
	./configure --prefix=/home/john/vips \
		--without-magick \
		--disable-introspection
$ G_DEBUG=gc-friendly vips copy ~/pics/k2.jpg x.jpg >& log

Build with the GCC auto-vectorizer and diagnostics (or just -O3):

$ FLAGS="-O2 -msse4.2 -ffast-math"
$ FLAGS="$FLAGS -ftree-vectorize -fdump-tree-vect-details"
$ CFLAGS="$FLAGS" CXXFLAGS="$FLAGS" \
	./configure --prefix=/home/john/vips 

Static analysis with:

$ cppcheck --force --enable=style . &> cppcheck.log

Dependencies

libvips has to have glib2.0-dev. Other dependencies are optional, see below.

Optional dependencies

If suitable versions are found, libvips will add support for the following libraries automatically. See ./configure --help for a set of flags to control library detection. Packages are generally found with pkg-config, so make sure that is working.

libtiff, giflib and libjpeg do not usually use pkg-config so libvips looks for them in the default path and in $prefix. If you have installed your own versions of these libraries in a different location, libvips will not see them. Use switches to libvips configure like:

./configure --prefix=/Users/john/vips \
	--with-giflib-includes=/opt/local/include \
	--with-giflib-libraries=/opt/local/lib \
	--with-tiff-includes=/opt/local/include \
	--with-tiff-libraries=/opt/local/lib \
	--with-jpeg-includes=/opt/local/include \
	--with-jpeg-libraries=/opt/local/lib

or perhaps:

CFLAGS="-g -Wall -I/opt/local/include -L/opt/local/lib" \
	CXXFLAGS="-g -Wall -I/opt/local/include -L/opt/local/lib" \
	./configure --without-python --prefix=/Users/john/vips 

to get libvips to see your builds.

vips8 Python binding

If gobject-introspection, python-gi-dev, and libgirepository1.0-dev are available, libvips will install the vips8 Python binding.

libjpeg

The IJG JPEG library. Use the -turbo version if you can.

libexif

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

giflib

The standard gif loader. If this is not present, vips will try to load gifs via imagemagick instead.

librsvg

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

libpoppler

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

libgsf-1

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, lcms

If present, vips_icc_import(), vips_icc_export() and vips_icc_transform() are available for transforming images with ICC profiles. If lcms2 is available it is used in preference to lcms, since it is faster.

Large files

libvips uses the standard autoconf tests to work out how to support large files (>2GB) on your system. Any reasonably recent unix should be OK.

libpng

If present, libvips can load and save png files.

ImageMagick, or optionally GraphicsMagick

If available, libvips adds support for loading all libMagick-supported image file types. Use --with-magickpackage=GraphicsMagick to build against graphicsmagick instead.

Imagemagick 6.9+ needs to have been built with --with-modules. Most packaged IMs are, I think, but if you are rolling your own, you'll need to pass this flag to configure.

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 using a package with such a large attack surface. You might prefer not to enable Magick support.

pangoft2

If available, libvips adds support for text rendering. You need the package pangoft2 in pkg-config --list-all.

orc-0.4

If available, vips will accelerate some operations with this run-time compiler.

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.

OpenEXR

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

OpenSlide

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

swig, python, python-dev

If available, we build the vips7 python binding.

Disclaimer

No guarantees of performance accompany this software, nor is any responsibility assumed on the part of the authors. Please read the licence agreement.