一个需求驱动的多线程图像处理库.zip

# libvips: an image processing library [](https://github.com/libvips/libvips/actions) [](https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=2&q=proj:libvips) [](https://scan.coverity.com/projects/jcupitt-libvips) [](https://gitter.im/libvips/devchat?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge) # Introduction libvips is a [demand-driven, horizontally threaded](https://github.com/libvips/libvips/wiki/Why-is-libvips-quick) image processing library. Compared to similar libraries, [libvips runs quickly and uses little memory](https://github.com/libvips/libvips/wiki/Speed-and-memory-use). libvips is licensed under the [LGPL 2.1+](https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html). It has around [300 operations](https://libvips.github.io/libvips/API/current/func-list.html) covering arithmetic, histograms, convolution, morphological operations, frequency filtering, colour, resampling, statistics and others. It supports a large range of [numeric types](https://libvips.github.io/libvips/API/current/VipsImage.html#VipsBandFormat), 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](https://libvips.github.io/libvips/API/current/using-from-c.html), [C++](https://libvips.github.io/libvips/API/current/libvips-from-C++.html), and the [command-line](https://libvips.github.io/libvips/API/current/using-cli.html). Full bindings are available for : | Language | Binding | |---|---| | Ruby | [ruby-vips](https://rubygems.org/gems/ruby-vips) | | Python | [pyvips](https://pypi.python.org/pypi/pyvips) | | PHP | [php-vips](https://github.com/libvips/php-vips) | | C# / .NET | [NetVips](https://www.nuget.org/packages/NetVips) | | Go | [govips](https://github.com/davidbyttow/govips) | | Lua | [lua-vips](https://github.com/libvips/lua-vips) | | Crystal | [crystal-vips](https://github.com/naqvis/crystal-vips) | | Elixir | [vix](https://github.com/akash-akya/vix) | libvips is used as an image processing engine by: | | |---| | [sharp (on node.js)](https://www.npmjs.org/package/sharp) | | [imgproxy](https://github.com/imgproxy/imgproxy) | | [bimg](https://github.com/h2non/bimg) | | [sharp for Go](https://github.com/DAddYE/vips) | | [Ruby on Rails](https://edgeguides.rubyonrails.org/active_storage_overview.html) | | [carrierwave-vips](https://github.com/eltiare/carrierwave-vips) | | [mediawiki](https://www.mediawiki.org/wiki/Extension:VipsScaler) | | [PhotoFlow](https://github.com/aferrero2707/PhotoFlow) | and others. The official libvips GUI is [nip2](https://github.com/libvips/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](https://github.com/libvips/libvips/releases). The [libvips website](https://libvips.github.io/libvips) has [detailed install notes](https://libvips.github.io/libvips/install.html). # Building from source libvips uses the [Meson build system](https://mesonbuild.com), version 0.56 or later. Meson can use [`ninja`](https://ninja-build.org), 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](https://github.com/dloebl/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 surfa