How to Install imagemagick on mac os x for rails 3
I love coding but sometimes it just gets frustrating when you're stuck on something particular for hours. In my case I were trying to add file uploads to my web app using paperclip and as soon as I were ready to upload an image rails returned an error saying I must install imagemagick. In today's post I am going to share with you all how I have gotten this to work and hopefully this saves you hours of trying to find the right solution.
Install gem
First things first, open your gemfile located in your rails root directory then add the following to your gemfile. Though this tutorial is fairly new I recommend checking the latest version to see where rmagick is currently at. gem 'rmagick', '2.13.1'
Install Homebrew
When getting your mac you notice mac's come without tons of programs which means you have to install them manually. After you have added rgmagick to your gemfile go to homebrew homepage.
Open your terminal and add the following code: /usr/bin/ruby -e "$(curl -fsSL https://raw.github.com/gist/323731)" After running the above command run this command. Should start installing imagmagick this take a bit of time. brew install imagemagick
Permission issues
If you get an error in rails saying
Errno::EACCES: Permission denied - /Users/path An error occured while installing rmagick (2.13.1), and Bundler cannot continue. Make sure that `gem install rmagick -v '2.13.1'` succeeds before bundling.
Go to the path where rmagick is(gems folder) and pull the folder to your desktop then create a new folder with the same name and finally copy the content from the first folder to your newly created folder. After you have successfully done so you should now have full permission. Finally go into your terminal and run bundle install command and everything shou
Image generation with RMagick and Single Responsibility Principle
Recently in one of our projects I was confronted with a feature related to sharing on Facebook. Facebook has an extremely simple API for this very purposes. It requires only a single parameter - API key. However, you can customize the text and the image in the Share dialog and Post by changing these values: title, description and image url.
A background image as a basis.
A random title taken from the record of certain model.
Logo of the web-service.
To achieve the goal I decided to use gem "rmagick". RMagick is an interface between the Ruby programming language and the ImageMagick and GraphicsMagick image processing libraries. It is a great tool in case you need to manipulate graphics from the code side. We are going to take an advantage of some cool features implemented in this gem.
So, let me get straight to the point. First of all, I have added gem "rmagick" to my Gemfile. Then, told Rails to install the new gem:
bundle install
Let's analyze what we're going to do before jumping into the code. Basically, we have two options for drawing something on the image: place some text on canvas and impose images surfaces. At first sight, the best solution is to construct a service that contains two actions for each mode of drawing. My new class is being instantiated in the following way:
class WatermarkedBackground BACKGROUND_PATH = "/path/to/background.jpg" attr_reader :text, :annotation, :logo private :text, :annotation, :logo def initialize(text, logo_path) @text = text @annotation = Magick::Draw.new.tap do |text| text.font = "Helvetica" text.pointsize = 60 text.font_weight = Magick::BoldWeight text.fill = "black" text.gravity = Magick::CenterGravity end @logo = Magick::Image.read(logo_path).first end def perform draw_text append_picture save_image end private def draw_text annotation.annotate(background, 0, 0, 0, 60, text) end def append_picture background.composite!(logo, 420, 20, Magick::OverCompositeOp) end def save_image background.write("/path/to/generated_image.jpg") end def background @background ||= Magick::Image.read(BACKGROUND_PATH).first end end
Let's take a look at what we've done here.
The first action draw_text prints our random content in the center of 'background.jpg'. The base player of this action is annotate function. It takes six arguments:
the image you want to annotate
the width and height of the rectangle for the positioned text
the two arguments are offsets for x, y axes respectively
the last one is the text for the annotation
I configured width and height are equal to zero. It indicates that the whole image should be used as an annotation area. The attribute gravity points out the position of text inside rectangle. In my case it is the center of rectangle. Also, I specify the font, the text color, size, and other properties of the text in initialize method.
The second action append_picture gives us the ability to blend two pictures into a single image. The main part here is composite! function. To push it into the work we should define four arguments. Three of them are pretty obvious: source image, x- and y- offsets relative to the upper-left corner of the background image. The last argument is a little bit tricky. It is associated with algorithm used to compose the first image with the second. The number of options is about 60 variants. You can review here documentation to figure out which one fits you best.
The last action save_image saves prepended image and automatically converts it to the extension that we specify. The call of
WatermarkedBackground.new( "The quick brown fox jumps over a lazy dog", "/path/to/logo.png" ).perform
gives me the desired result.
After I have dotted the i's and crossed the t's it's time to ask: Is this the best way to organize the code? Unfortunately, not. Now I have single class that contains the both behavior and configurations for the image generation. However, a class should do the smallest possible useful thing; that is, it must not violate a single responsibility principle. It would be difficult to test actions of my class in isolation of the text properties. I'd have to stub too many methods.
So it makes sense to separate the configurations for the annotation text in the independent class that is wrapped the RMagick standard action annotate, as shown bellow:
class TextImage attr_reader :text private :text def initialize(text) @text = text end def annotate(*args) draw.annotate(*args, text) end private def draw Magick::Draw.new.tap do |text| text.font = "Helvetica" text.pointsize = 60 text.font_weight = Magick::BoldWeight text.fill = "black" text.gravity = Magick::CenterGravity end end end
And class can be rewritten in the following way.
class WatermarkedBackground BACKGROUND_PATH = "/path/to/background.jpg" attr_reader :logo, :text, :background private :logo, :text, :background delegate :write, to: :image def initialize(text:, logo_path:) @text = text @logo = Magick::Image.read(logo_path).first @background = Magick::Image.read(BACKGROUND_PATH).first end def image @image ||= text.annotate(composited_background, 0, 0, 0, 0) end private def composited_background background.composite(logo, 420, 20, Magick::OverCompositeOp) end end
As you see I decoupled my code and reduce dependencies. This polishing allows me to remove the responsibility for some of RMagick methods. No need to stub them for the testing WatermarkedBackground anymore. It is substituted by only one responsibility TextImage which can be easily reused without duplication.
WatermarkedBackground.new( text: TextImage.new("The quick brown fox jumps over a lazy dog"), logo_path: "/path/to/logo.png" ).write("/path/to/generated_image.jpg")
Check out the result of my work here. Nevertheless, RMagick has a bunch of cool features. They can be found at their official web-site.
P.S. Special thanks go to Vladimir Mikhailov for taking the time to review this post and give terrific advice that lead to the great improvement.
I get the error shown below when attempting to install the rmagick gem. I am on Snowleopard 10.6 using RVM, Ruby 1.9.2-head and Rails 3.05. Responses to similar questions recommended installing ImageMagick, which I successfully did. Other suggested installing the “libmagick9-dev library”, however, I can not figure out how to do this.
When I try do install rmagick I get the following error message:
Can't install RMagick 2.13.1. Can't find MagickWand.h. *** extconf.rb failed *** Could not create Makefile due to some reason, probably lack of necessary libraries and/or headers. Check the mkmf.log file for more details. You may need configuration options.
How to: rmagick gem install "Can't find Magick-config"
rmagick gem install "Can’t find Magick-config"
I get the error shown below when attempting to install the rmagick gem. I am on Snowleopard 10.6 using RVM, Ruby 1.9.2-head and Rails 3.05. Responses to similar questions recommended installing ImageMagick, which I successfully did. Other suggested installing the “libmagick9-dev library”, however, I can not figure out how to do this.
I'm working on a fun project suggested to me by a colleague. To spike it I decided to implement a quick test script to figure out what will be needed to implement its core feature. I'd talk more about it in the future but suffice it to say that one of the requirements is image manipulation.
The best game in town where image manipulation is concerned seems to be ImageMagick. And based on my limited research the best Ruby binding is RMagick.
I had a little trouble while installing the RMagick gem so I thought I'd just document the process for future me (and whoever else).
sudo apt-get install imagemagick
sudo apt-get install libmagickwand-dev
gem install rmagick
The problem occurred in Step 2 for me and it took me a while to find that solution.
[Solved] Trouble installing rmagick gem on mac 10.9
After upgrading to Mavericks, I ran into the problem of being able to bundle install due to rmagick install failure. The solution of mine is: 1) brew update; 2) brew unlink imagemagick; 3) brew install imagemagick.
The reason may be Mavericks shifts from ibstdc++ to libc++. The change of Mavericks from Lion is even more dramatic than I thought. So, please prepare for the surprises if you upgrade it anyway like I did.
