rails_magick

RailsMagick

RailsMagick is a simple Rails interface with command line ImageMagick to do very common image manipulation functions.

At the moment, RailsMagick does three things:

• Identifies the image. Returns the image type, width and height.
• Resamples the image. Pass it a bounding box and it will resample the image to fit the bounding box.
• Create a thumbnail. Pass it a bounding box and it will FILL the bounding box with the image and crop it to the dimensions of the bounding box.

Usage

Installation

Make sure that you have ImageMagick installed as a command line tool. You need to be able to run "identify" and "convert" commands from the command line, as the user that will run Rails. To test, just type "identify" and "convert" in the command line terminal to see if they are installed.

Add the following to your Gemfile:

gem 'rails_magick'

Run 'bundle install' from the command line to update your gems.

Identify

Gives you information about an image.

result = RailsMagick.identify(path_to_file)

This will return a hash.

puts result[:type]
puts result[:width]
puts result[:height]

Resample

Resamples an image proportionally to fit within the bounding box dimensions. Will raise a RuntimeError if it fails, or IOError if the file doesn't exist.

Parameters: infile (path to file), outfile (path to file), width, height, quality (default is 80)

begin
  RailsMagick.resample(infile, outfile, 640, 640, 80)
rescue Exception => e
  puts e.message
end

Create thumbnail

Will resample and crop the image proportionally to FILL the bounding box dimensions. Will raise a RuntimeError if it fails, or IOError if the file doesn't exist.

Parameters: infile (path to file), outfile (path to file), width, height, quality (default is 80)

begin
  RailsMagick.create_thumbnail(infile, outfile, 100, 100, 80)
rescue Exception => e
  puts e.message
end