Replacing RMagick with mini_magick with Paperclip - ruby-on-rails

Question

I'm using RMagick and loving it, but it is eating up huge amounts of memory. Even a simple script would use over 100MB of Ram. On my local machine this isn't a problem, but on heroku my app crashes when a few users simultaneously upload Pictures.
I found mini_magick and trying to replace it in my Model's, but can't find a solution. This is my current Process Flow:
# Validations
validates :scr, presence: true
# Paperclip
has_attached_file :scr,
styles: {
index: ['220x170#', :jpg, quality: :better],
show: ['1000', :jpg, quality: :better],
original: ['100%', :jpg, quality: :better],
directionals: ['115x70#', :jpg]
},
convert_options: {
show: '-quality 90 -unsharp 3x0.4+0.4+0 -interlace Plane',
index: '-quality 90 -unsharp 3x0.4+0.4+0 -interlace Plane',
original: '-quality 90 -interlace Plane',
directionals: '-quality 90 -interlace Plane'
},
processors: [:thumbnail, :compression]
# Paperclip Validation
validates_attachment_content_type :scr, content_type: ['image/jpg', 'image/jpeg', 'image/png']
How can i replace RMagick and let Mini_magick do the Magic ?

Answer 1

remove Rmagick from gemfile.add minimagick to your gemfile and start using it
Add the gem to your Gemfile:
gem "mini_magick"
bundle install
####now start using it with callback/observer
image = MiniMagick::Image.open("input.jpg")
image.resize "100x100"
image.write "output.jpg"
OR
you can use delayed_paperclip for the same so that at runtime convert only those styles that you need on next page....rest put it in background for conversion using it without changing the code.
process_in_background :avatar, :only_process => [:show,:original,:directionals]
##assuming you next page only need style :index..