Skip to content
Ruby extension for the libvips image processing library.
Branch: master
Clone or download
Latest commit b0ca790 Jun 13, 2019
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
example more rubocop Jun 13, 2019
lib more rubocop Jun 13, 2019
spec more rubocop Jun 13, 2019
.gitignore Ignore Gemfile.lock Jun 7, 2016
.rubocop.yml more rubocop Jun 12, 2019
.rubocop_todo.yml more rubocop Jun 13, 2019
.travis.yml reenable rubocop on commit Jun 12, 2019
.yardopts add .yardopts Jul 7, 2016
CHANGELOG.md fix various rubocop warnings Jun 12, 2019
Gemfile Defer to gemspec for gems Jun 7, 2016
LICENSE.txt first commit of 1.0 Jun 6, 2016
README.md update links for new home Sep 27, 2018
Rakefile
TODO fix various rubocop warnings Jun 12, 2019
VERSION bump version, plus better write_to_memory Jun 12, 2019
install-vips.sh update links for new home Sep 27, 2018
ruby-vips.gemspec more rubocop Jun 12, 2019

README.md

ruby-vips

Gem Version Build Status

This gem provides a Ruby binding 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. For example, 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

See also benchmarks at the official libvips website.

Requirements

Install

It's just:

$ gem install ruby-vips

or include it in Gemfile:

gem 'ruby-vips'

On Windows, you'll need to set the RUBY_DLL_PATH environment variable to point to the libvips bin directory.

Take a look in examples/. There is full API documentation.

Example

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_filename

Older versions

There are two older versions of this gem.

The 0.3-stable branch is written in C and supports a different API. It still works, but is only maintained for compatibility.

The 1.0-stable branch is based on gobject-introspection rather than ffi. It supports the same API as the current version, but is harder to install, less portable, slower, and less stable.

You can’t perform that action at this time.