Ruby extension for the libvips image processing library.

Programs that use ruby-vips 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 ruby-vips is parallel, it's quick, and because it doesn't need to keep entire images in memory, it's light.