attachment_fu and minimagick resize bug

In one of my latest projects i was using the attachement_fu plugin to handle image uploads.
The attachement_fu plugin enables the option to select an image processor engine between ImageScience, Rmagick add MiniMagick:

1. Rmagick
   Kinda bulky, leaking but fully functional
   
2. MiniMagick
   Simple version of Rmagick, simple and small.
3. ImageSceince
   Small, nice, and quick.

i decided to use MiniMagick as my processor, i installed the gem:

 sudo gem install mini_magick

and added a specific :processor option to my Logo model.

has_attachment :content_type => :image, 
                   :storage => :file_system, 
                   :max_size => 2.megabytes,
                   :resize_to => 'x100',
                   :processor => :mini_magick

but when i was uploading an image, i was was expecting it to be resized based on the options i specified in the model. imagine how surprised i was when i found out that the image is not being resized.

checking the log found the following error:

Exception working with image: ImageMagick command (identify "/var/folders/Bv/Bvbna8-OH548ZWju8naF4U+++TI/-Tmp-/minimagick11451-0") failed: Error Given 32512

Googling it didn't help me much (except from finding other people with the same problem), so i decided to switch to ImageScience instead (RMagick is out of the question of course).

 sudo gem install image_science

this will include all most all dependencies, the freeImage dependency is also needed.
us mac/darwin users can simply use port:

  sudo port selfupdate
  sudo port install freeimage

now change the processor in the model

has_attachment :content_type => :image, 
                   :storage => :file_system, 
                   :max_size => 2.megabytes,
                   :resize_to => 'x100',
                   :processor => :image_science

and now it's working. yeah!.

Rails Tip: image_tag, SEO Optimization

when you use rails's image_tag, by default it sets the HTML attributes of alt and title to the filename of the image. so for

image_tag 'dscn0001.jpg'

will produce the following html something like that

<img src="images/dscn0001.jpg" alt="dscn0001" />


the alt attribute for image tag is meant to explain the content of the image in case the actual image was not found, or for non-graphic browsers.

The default value for the alt attribute should not be used, unless the file name does not really supply information about the image. my suggestion is to use the :alt option in the image_tag helper.

important: do not attempt to use the alt for keywords heaping ('elad-rails-blog-ruby.jpg'), this will not help you in your SEO.