Saving the images Dimensions (width and height) in Paperclip?

Question

Any Paperclip wizards out there know if you can when using Paperclip to save an image, also save the image dimensions (width and height) in 2 extra fields? How do you get such data during the Paperclip upload process?

Answer 1

Just for the sake of completeness, even though previous answers already show good enough suggestions.

You can utilize Paperclip event handlers instead of Rails callbacks. In this case, size will be recalculated only when image changes. (If you're using S3 for storage, this can save quite some time)

has_attached_file :image, :styles => ... after_post_process :save_image_dimensions  def save_image_dimensions   geo = Paperclip::Geometry.from_file(image.queued_for_write[:original])   self.image_width = geo.width   self.image_height = geo.height end 

Image don't even have to be downloaded from S3 (or read from a file), paperclip provides it to event handler itself.

See Events section of the readme for details.

Answer 2

When a user uploads an image with paperclip I process it with the following model:

class Picture < ActiveRecord::Base   has_attached_file :pic, :styles => { :small => "100x100>" }, :whiny => true   after_save :save_geometry    def save_geometry     unless @geometry_saved       self.original_geometry = get_geometry(:original)       self.small_geometry = get_geometry(:small)       @geometry_saved = true       self.save     end   end    def get_geometry(style = :original)     begin       Paperclip::Geometry.from_file(pic.path(style)).to_s     end   end end 

The get_geometry function calls ImageMagick identify to find the geometry of your original and resized images.

I cache the results in a database field. For example if I uploaded an image that was 1024x768 my cached fields would contain:

original_geometry = "1024x768" small_geometry = "100x75"