This gem is a Ruby binding for the libvips image processing library. It has been tested on Linux, macOS and Windows, and with ruby 2, ruby 3 and jruby. It uses ruby-ffi to call functions in the libvips library.
libvips is a demand-driven, horizontally threaded image processing library. Compared to similar libraries, libvips runs quickly and uses little memory. libvips is licensed under the LGPL 2.1+.
Install the libvips binary with your package manager (eg. apt install libvips42 or perhaps brew install vips, see the libvips install
instructions) then install
this gem with:
gem install ruby-vips
Or include gem "ruby-vips" in your gemfile.
The gemspec will pull in the msys libvips for you, so all you need is:
gem install ruby-vips
Or include gem "ruby-vips" in your gemfile.
Tested with the ruby and msys from choco, but others may work.
require "vips"
im = Vips::Image.new_from_file filename
# 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
im = im.embed 100, 100, 3000, 3000, extend: :mirror
# multiply the green (middle) band by 2, leave the other two alone
im *= [1, 2, 1]
# make an image from an array constant, convolve with it
mask = Vips::Image.new_from_array [
[-1, -1, -1],
[-1, 16, -1],
[-1, -1, -1]], 8
im = im.conv mask, precision: :integer
# finally, write the result back to a file on disk
im.write_to_file output_filenameThere are full API docs for ruby-vips on rubydoc. This sometimes has issues updating, so we have a copy on the gh-pages for this site as well, which should always work.
See the Vips section in the docs for a tutorial introduction with
examples.
The libvips reference manual has a complete explanation of every method.
The example/
directory has some simple example programs.
The benchmark at vips-benchmarks loads a large image, crops, shrinks, sharpens and saves again, and repeats 10 times.
real time in seconds, fastest of five runs
benchmark tiff jpeg
ruby-vips.rb 0.85 0.78
image-magick 2.03 2.44
rmagick.rb 3.87 3.89
peak memory use in kb
benchmark peak RES
ruby-vips.rb 43864
rmagick.rb 788768