Embed raster image file (JPG, PNG, GIF, BMP) in SVG file

embed_raster_image_in_svg.rb

require 'base64'
require 'fastimage'

# This is not raster-to-vector conversion; this is putting a raster in a vector 
# suit. If you find yourself in need of this information, something is very 
# wrong. Something is very wrong.

def embed_raster_image_in_svg(input_image ="raster.jpg", 
                              output_image="raster_in_vector.svg")
  dimensions = FastImage::size(input_image)
  width  = dimensions[0]
  height = dimensions[1]
  
  mime_type = case File.extname(input_image).downcase
  when ".jpg", ".jpeg"
    "image/jpeg"
  when ".gif"
    "image/gif"
  when ".png"
    "image/png"
  when ".bmp"
    "image/bmp"
  else
    raise
  end

  data = Base64::encode64 File.binread(input_image)

  data = %{
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
  <image id="embedded-raster" width="#{width}" height="#{height}" xlink:href="data:#{mime_type};base64,#{data}" />
</svg>
}.strip

  File.write(output_image, data)

  return data
end