A ruby wrapper for ImageMagick or GraphicsMagick command line.
Tested on the following Rubies: MRI 1.8.7, 1.9.2, 1.9.3, 2.0.0, REE, JRuby, Rubinius.
Add the gem to your Gemfile:
gem "mini_magick"
I was using RMagick and loving it, but it was eating up huge amounts of memory. Even a simple script would use over 100MB of Ram. On my local machine this wasn't a problem, but on my hosting server the ruby apps would crash because of their 100MB memory limit.
Using MiniMagick the ruby processes memory remains small (it spawns ImageMagick's command line program mogrify which takes up some memory as well, but is much smaller compared to RMagick)
MiniMagick gives you access to all the commandline options ImageMagick has (Found here http://www.imagemagick.org/script/mogrify.php)
Want to make a thumbnail from a file...
image = MiniMagick::Image.open("input.jpg")
image.resize "100x100"
image.write "output.jpg"
Want to make a thumbnail from a blob...
image = MiniMagick::Image.read(blob)
image.resize "100x100"
image.write "output.jpg"
Got an incoming IOStream?
image = MiniMagick::Image.read(stream)
Want to make a thumbnail of a remote image?
image = MiniMagick::Image.open("http://www.google.com/images/logos/logo.png")
image.resize "5x5"
image.format "gif"
image.write "localcopy.gif"
Need to combine several options?
image = MiniMagick::Image.open("input.jpg")
image.combine_options do |c|
c.sample "50%"
c.rotate "-90>"
end
image.write "output.jpg"
Want to composite two images? Super easy! (Aka, put a watermark on!)
image = Image.open("original.png")
result = image.composite(Image.open("watermark.png", "jpg")) do |c|
c.gravity "center"
end
result.write "my_output_file.jpg"
Want to manipulate an image at its source (You won't have to write it out because the transformations are done on that file)
image = MiniMagick::Image.new("input.jpg")
image.resize "100x100"
Want to get some meta-information out?
image = MiniMagick::Image.open("input.jpg")
image[:width] # will get the width (you can also use :height and :format)
image["EXIF:BitsPerSample"] # It also can get all the EXIF tags
image["%m:%f %wx%h"] # Or you can use one of the many options of the format command
For more on the format command see http://www.imagemagick.org/script/command-line-options.php#format
Want to composite (merge) two images?
first_image = MiniMagick::Image.open "first.jpg"
second_image = MiniMagick::Image.open "second.jpg"
first_image.composite(second_image) do |c|
c.compose "Over" # OverCompositeOp
c.geometry "+20+20" # copy second_image onto first_image from (20, 20)
end
first_image.write "output.jpg"
Unlike RMagick, MiniMagick is a much thinner wrapper around ImageMagick.
- To piece together MiniMagick commands is to refer to the Mogrify Documentation. For instance you can use the
-flop
option asimage.flop
. - Operations on a MiniMagick image tend to happen in-place as
image.trim
, whereas RMagick has both copying and in-place methods likeimage.trim
andimage.trim!
. - Top open files with MiniMagick you use
MiniMagick::Image.open
as you wouldMagick::Image.read
. To open a file and directly edit it, useMiniMagick::Image.new
.
When passing in a blob or IOStream, Windows users need to make sure they read the file in as binary.
# This way works on Windows
buffer = StringIO.new(File.open(IMAGE_PATH,"rb") { |f| f.read })
MiniMagick::Image.read(buffer)
# You may run into problems doing it this way
buffer = StringIO.new(File.read(IMAGE_PATH))
Simply set
MiniMagick.processor = :gm
And you are sorted.
You must have ImageMagick or GraphicsMagick installed.
Version 3.5 doesn't work in Ruby 1.9.2-p180. If you are running this Ruby version use the 3.4 version of this gem.