MojoMagick
MojoMagick is a "dog simple, do very little" image library. It is basically a couple of stateless module methods that make it somewhat more convenient than calling ImageMagick by hand.
The main reason to use MojoMagick is that you should consolidate your ImageMagick calls into one place, so why not do it here? If you improve on this tool, send me the patch.
This tool came about because I wanted a fast, simple, lightweight, nothing-goes-wrong-with-it- because-it's-too-simple-to-break image tool.
Using it
Add to your Gemfile
gem 'mojo_magick'
Require it in your ruby code
require 'mojo_magick'
Go to town! Check out a couple of simple examples, here
Examples
Image Resizing
Obtain the size of an image (assuming image is "120wx222h")
dimensions = MojoMagick::get_image_size(test_image)
# ==> dimensions now holds a hash: {:height => 120, :width => 222}
Resize an image so that it fits within a 100w x 200h bounding box
(Note: this will scale an image either up or down to fit these dimensions which may not be what you want.) In this example, we overwrite our image, but if you pass in a different file for the second file name, a new file will be created with the resized dimensions
MojoMagick::resize('/img/test.jpg', '/img/test.jpg', {:width=>100, :height=>200})
Resize an image so that it fills a 100 x 100 bounding box
After this transformation, your image's short side will be 100px. This will preserve the aspect ratio.
MojoMagick::resize('/img/infile.jpg', '/img/outfile.jpg', {:width=>100, :height=>100, :fill => true})
Resize an image so that it fills and is cropped to a 100 x 100 bounding box
After this transformation, your image will be 100x100. But it does not distort the images. It crops out of the Center.
MojoMagick::resize('/img/infile.jpg', '/img/outfile.jpg', {:width=>100, :height=>100, :fill => true, :crop => true})
Code sample of how to shrink all jpg's in a folder
require 'mojo_magick'
image_folder = '/tmp/img'
Dir::glob(File::join(image_folder, '*.jpg')).each do |image|
begin
# shrink all the images *in place* to no bigger than 60pix x 60pix
MojoMagick::shrink(image, image, {:width => 60, :height => 60})
puts "Shrunk: #{image}"
rescue MojoMagick::MojoFailed => e
STDERR.puts "Unable to shrink image '#{image}' - probably an invalid image\n#{e.message}"
rescue MojoMagick::MojoMagickException => e
STDERR.puts "Unknown exception on image '#{image}'\n#{e.message}"
end
end
Setting Memory/Resource limits for ImageMagick
Be sure you're upgraded to the current release of ImageMagick.
set limits on disk, area, map and ram usage obtain/print a hash of default limits:
puts MojoMagick::get_default_limits.inspect
current_limits shows same values:
puts MojoMagick::get_current_limits.inspect
MojoMagick::set_limits(:area => '32mb', :disk => '0', :memory => '64mb', :map => '32mb')
puts MojoMagick::get_current_limits.inspect
As of ImageMagick 6.6, you also have the ability to set :threads
and :time
. Read ImageMagick docs on limits for more info.
For more complex operations (thanks to Elliot Nelson for adding this code to the system)
Two command-line builders, #convert and #mogrify, have been added to simplify complex commands.
using #convert
MojoMagick::convert('source.jpg', 'dest.jpg') do |c|
c.crop '250x250+0+0'
c.repage!
c.strip
c.set 'comment', 'my favorite file'
end
# Equivalent to:
MojoMagick::raw_command('convert', 'source.jpg -crop 250x250+0+0 +repage -strip -set comment "my favorite file" dest.jpg')
using #mogrify
MojoMagick::mogrify('image.jpg') {|i| i.shave '10x10'}
# Equivalent to:
MojoMagick::raw_command('mogrify', '-shave 10x10 image.jpg')
# Example showing some additional options:
# assuming binary data that is rgb, 8bit depth and 10x20 pixels, :format => :rgb, :depth => 8, :size => '10x20'OAu
MojoMagick::convert do |c|
c.file 'source.jpg'
c.blob my_binary_data, :format => :rgb, :depth => 8, :size => '10x20'
c.append
c.crop '256x256+0+0'
c.repage!
c.file 'output.jpg'
end
# Use .file to specify file names, .blob to create and include a tempfile. The
# bang (!) can be appended to command names to use the '+' versions
# instead of '-' versions.
Create a brand new image from data
binary_data = '1111222233334444'
MojoMagick::convert do |c|
c.rgba8 binary_data, :format => :rgba, :depth => 8, :size => '2x2'
c.file 'output.jpg'
end
Get a list of available fonts
fonts = MojoMagick::available_fonts
fonts.first
=> #<MojoMagick::Font:0x000001015a8b90 @name="AvantGarde-Book", @family="AvantGarde", @style="Normal", @stretch="Normal", @weight="400", @glyphs="/usr/local/share/ghostscript/fonts/a010013l.pfb">
Create a new image with text
Note: Use with care. If you don't have fonts installed ImageMagick can spin off wildly leaving MojoMagick not knowing what to do. For Unix/MacOSX, you should install freetype
and ghostscript
.
MojoMagick::convert(nil, fname) do |c|
c.background 'black'
c.fill 'white'
c.gravity 'center'
c.pointsize 80
c.size '200x200'
c.label 'the bird is the word'
end
Generate a composite
MojoMagick::convert(nil, 'composite_out.png') do |c|
c.size '200x200'
c.image_block do # first layer
c.background 'blue'
c.fill 'white'
c.gravity 'northwest'
c.label 'NW'
end
c.image_block do # second layer
c.background 'transparent'
c.fill 'red'
c.gravity 'southeast'
c.label 'SE'
end
c.composite
end
Dependencies
This library has (in the past) been good for ruby 1.8.7 and beyond. Recent mods (as of 0.5.x) will require a more recent ruby (>1.9.3).
If you're running on 1.8.7, you should be able to safely use 0.4.3
Do this by pinning it in your Gemfile
gem 'mojo_magick', '0.4.3'
Availablility
- Github Repo This is the current canonical branch.
- Issues/Pull Requests can be submitted through the above repository.
Contributions
Got a fix? Got a feature?
- fork it
- make a branch (named appropriately)
- write your code
- write your tests
- test it (
rake
will run the tests) - submit a pull request
Note: please don't change the version. We'll do that when we merge in the new code
Recent Changes
Version 0.6.7
- Bundle update
Version 0.6.6
- Bundle update
Version 0.6.5
- Bundle update
Version 0.6.4
- Fix issue with
identity -list font
returning exit code 1 on some systems (Ubuntu) with PR ##35 35
Version 0.6.3
- Major cleanup and refactor (#33)
- Deprecated
MojoMagick.get_fonts
in favor ofMojoMagick.available_fonts
- Moved
raw_command
andexecute
andexecute!
methods into their own module (and added deprecation warnings) - Renamed
Util::Parser
toUtil::FontParser
because that's what it does - Overall rubocop and ruby clean up
Version 0.6.2
- fix
annotate
option. Now it takes keyword arguments for geometry.
Version 0.6.1
- pushed and yanked - defunct version
Version 0.6.0
- general cleanup and update gems - ready for ImageMagick 7
- dumped resource limit handling
- PR #29, #30
Version 0.5.6
- add
get_format
method to help with quoted source file
Version 0.5.5
- Refactor raw_command into execute! and execute methods so that for cases where we don't care about exit status, it can be easily ignored
Version 0.5.4
- Include image magick commandline failure from raw_command (on failure)
- moved to Popen3
- added checks for Popen3 on windows
- updated README to include info about submissions
- probably no good for ruby 1.8.7 anymore
Version 0.5.1
- add
LICENSE.txt
and update README - add
examples/
directory - add support for fonts
- add support for building multi-layer images with image blocks (no explicit temp file creation)
- Moved repo to rcode5 Current support and maintenance is happening here.
- added
simplecov
for test coverage reports
Versions 0.4.x
- Add rake tasks for gem building and tests
- code cleanup
- better handling of
gravity
parameter
Version 0.3.0
- Add new github repo
- added gemspec for building gem with bundler
- updated tests for ImageMagick 6.6
- added ability to do fill + crop resizing
- bumped version to 0.3.0
- new github repo
References
- Original SVN MojoMagick repository - Initiated and developed by Steve Midgley
- ImageMagick
- FreeType
- Ghostscript
Copyright (c) 2013 Jon Rogers Copyright (c) 2008 Steve Midgley, released under the MIT license Credit to Elliot Nelson for significant code contributions. Thanks Elliot!