Writing bindings for libvips 3 VIPS Library Binding How to write bindings for libvips The C source code to libvips has been marked up with special comments describing the interface in a standard way. These comments are read by gobject-introspection when libvips is compiled and used to generate a typelib, a description of how to call the library. Many languages have gobject-introspection packages: all you need to do to call libvips from your favorite language is to start g-o-i, load the libvips typelib, and you should have the whole library available. For example, from Python it's as simple as: from gi.repository import Vips libvips used in this way is likely to be rather bare-bones. For Python, we wrote a set of overrides which layer a more Pythonesque interface on top of the one provided for libvips by pygobject. These overrides are simply a set of Python classes, there's no magic. You are likely to want to do the same for your language. A second problem is that the libvips C API makes heavy use of varargs to pass optional parameters to operations. For example, in C you can write: VipsImage *in = vips_image_new_from_file (filename, NULL); VipsImage *out; vips_embed(in, &out, 10, 10, 100, 100, "extend", VIPS_EXTEND_COPY, NULL); to call embed with the optional parameter extend. varargs parameter lists are not supported by gobject-introspection, so you'll need to find some other way to call embed. If you are writing a language binding, you won't need these. Instead, make a new operation with vips_operation_new() (all it does is look up the operation by name with vips_type_find(), then call g_object_new() for you), then use vips_argument_map() and friends to loop over the operation's arguments setting them. Once you have set all arguments, use vips_cache_operation_build() to look up the operation in the cache and either build or dup it. If something goes wrong, you'll need to use vips_object_unref_outputs() and g_object_unref() to free the partially-built object.