Exif Fu

Location: United States, Chicago

This comes from one project that required reading exif tags for image rotation

Exif Fu assumes you’re using attachment_fu as your file handler (thus exif_fu), although it is easy enough to hack the library to use any other file library.

Exif Fu requires ExifTool by Phil Harvey (http://www.sno.phy.queensu.ca/~phil/exiftool/) and MiniExifTool (http://miniexiftool.rubyforge.org/) which you can install with gem install mini_exiftool

Example

All you need to do is add exif_fu to your model and you’re ready to go. Here is one example:

class Photo < ActiveRecord::Base

exif_fu

has_attachment :content_type => :image,
               :storage => :file_system,
               :processor => :mini_magick,
               :size => 500..5.megabytes,
               :path_prefix => "public/#{table_name}",
               :thumbnails => {:medium => '600x600>', :thumb => '100x100>' }

validates_as_attachment

end

Usage

Once you’ve setup your model, all you have to do is call some of the methods on the model, some examples:

photo.iso would reutrn “800”

photo.shot_by would reutrn “Matthew Vincent”

photo.aperture would reutrn 4.0

photo.exif_tag(“MyCustomExifTag”) would reutrn “You got your tag”

You can see the rest of the included methods in the exif_fu.rb library, or just use the exif_tag to call any exif tag you want to. Please note that exif tags are case sensitive.