NetVips

This NuGet package provides a .NET binding for the libvips image processing library.

This binding passes the vips test suite cleanly with no leaks on Windows, macOS and Linux.

We have formatted docs online here:

https://kleisauke.github.io/net-vips/

How it works

Programs that use NetVips don't manipulate images directly, instead they create pipelines of image processing operations building on a source image. When the end of the pipe is connected to a destination, the whole pipeline executes at once, streaming the image in parallel from source to destination a section at a time.

Because NetVips is parallel, it's quick, and because it doesn't need to keep entire images in memory, it's light. For example, the NetVips benchmark:

NetVips.Benchmarks

Loads a large image, shrinks by 10%, sharpens, and saves again. On this test NetVips is around 14 times faster than Magick.NET and 5 times faster than ImageSharp.

The libvips documentation has a chapter explaining how libvips opens files which gives some more background.

Supported platforms

• .NET Framework (4.5 and higher)
• .NET Core (.NETStandard 2.0 and higher on Windows, Linux and macOS)
• Mono

Install

You need the libvips shared library on your library search path, version 8.2 or later. There are separate NuGet packages that will contain the pre-compiled libvips binaries for the most common platforms (see this repo for details):

	NuGet Package¹
Windows 64-bit
Windows 32-bit
Windows ARM64
Linux x64 glibc²
Linux x64 musl³
Linux ARM64v8
Linux ARMv7
macOS x64

¹ The version number of these NuGet packages is in sync with libvips' version number.
² Uses glibc as the standard C library (Ubuntu, Debian, etc).
³ Uses musl as the standard C library (Alpine, Gentoo Linux, etc).

Then just install this package, perhaps:

Install-Package NetVips

To test your install, try this test program:

if (ModuleInitializer.VipsInitialized)
{
    Console.WriteLine($"Inited libvips {NetVips.Version(0)}.{NetVips.Version(1)}.{NetVips.Version(2)}");
}
else
{
    Console.WriteLine(ModuleInitializer.Exception.Message);
}
Console.ReadLine();

If NetVips was able to find the libvips shared library, you should see:

Inited libvips [VERSION_NUMBER]

However, if you see something else, NetVips was unable to initialize libvips. This can happen for a variety of reasons, even though most of the times it's because NetVips was not able to find libvips or due to x86/x64 architecture problems:

Example

using NetVips;

using var im = Image.NewFromFile("image.jpg", access: Enums.Access.Sequential);

// put im at position (100, 100) in a 3000 x 3000 pixel image, 
// make the other pixels in the image by mirroring im up / down / 
// left / right, see
// https://libvips.github.io/libvips/API/current/libvips-conversion.html#vips-embed
using var embed = im.Embed(100, 100, 3000, 3000, extend: Enums.Extend.Mirror);

// multiply the green (middle) band by 2, leave the other two alone
using var multiply = embed * new[] { 1, 2, 1 };

// make an image from an array constant, convolve with it
using var mask = Image.NewFromArray(new[,]
{
    {-1, -1, -1},
    {-1, 16, -1},
    {-1, -1, -1}
}, 8);
using var convolve = multiply.Conv(mask, precision: Enums.Precision.Integer);

// finally, write the result back to a file on disk
convolve.WriteToFile("output.jpg");