svg2img

Svg2img

Convert SVG to image. Uses a bundled native binary, and requires no external dependencies. Supported output formats for now:

• png
• jpg
• webp
• gif

Installation

Add the svg2img gem to your Gemfile and run bundle install:

gem "svg2img"

Alternatively, you can install the gem manually:

gem install svg2img

Precompiled gems

We recommend installing the svg2img precompiled gems available for Linux and macOS. Installing a precompiled gem avoids the need to compile from source code, which is generally slower and less reliable.

When installing the svg2img gem for the first time using bundle install, Bundler will automatically download the precompiled gem for your current platform. However, you will need to inform Bundler of any additional platforms you plan to use.

To do this, lock your Bundle to the required platforms you will need from the list of supported platforms below:

bundle lock --add-platform x86_64-linux # Standard Linux (e.g. Heroku, GitHub Actions, etc.)
bundle lock --add-platform x86_64-linux-musl # MUSL Linux deployments (i.e. Alpine Linux)
bundle lock --add-platform aarch64-linux # ARM64 Linux deployments (i.e. AWS Graviton2)
bundle lock --add-platform x86_64-darwin # Intel MacOS (i.e. pre-M1)
bundle lock --add-platform arm64-darwin # Apple Silicon MacOS  (i.e. M1)

Usage

require "svg2img"
Svg2Img.process_svg(svg_string, options)

Example usage:

require "svg2img"

circle_svg = <<~SVG
  <svg xmlns="http://www.w3.org/2000/svg" width="100" height="100">
    <circle cx="50" cy="50" r="40" stroke="black" stroke-width="3" fill="red" />
  </svg>
SVG
png_path = Svg2Img.process_svg(circle_svg, format: :png)
# png_path is a path to the generated PNG file

# Rails example
data = Rails.cache.fetch([some, deps]) do
  png_path = Svg2Img.process_svg(circle_svg, format: :png, size: proc {|_svg_width, _svg_height| [256, 256]})
  png_data = File.binread(png_path)
  File.delete(png_path)
  png_data
end
send_data(png_data, type: 'image/png', disposition: 'inline')

Options

• format - output format, one of :png, :jpg, :webp, :gif
• output_path - path to the output image. If not provided, a temporary file will be created and the path to it will be returned.
• size - size of the output image as a proc that receives the width and height of the SVG and returns an array with the width and height of the output image. If the provides size has a different aspect ratio than the SVG, the image will be resized to fit in the center of the provided size. If not provided, the output image will have the same size as the SVG.
• super_sampling - supersample factor. The output image will be rendered super_sampling times larger than the SVG and then resized to the desired size. This can be used to improve the quality of the output image. Default is 2. Must be a power of 2. 1 means no super sampling.

Development

After checking out the repo, run bin/setup to install dependencies. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/0rvar/svg2img-rb.

License

The gem is available as open source under the terms of the MIT License.