Retrieving Image Height with Carrierwave

Ruby on Rails - Carrierwave get the image dimension width and height

You have to install ImageMagick, RMagick or MiniMagick. Then you open the file (image) before you can find out its height.

Example: https://github.com/jnicklas/carrierwave#conditional-versions (see the is_landscape? method), copied here:

  def is_landscape? picture
    image = MiniMagick::Image.open(picture.path)
    image[:width] > image[:height]
  end

Or this other related question:

Carrierwave and mini_magick finding widths & height

Retrieving image height with CarrierWave

You can adjust and use the method described here: http://code.dblock.org/carrierwave-saving-best-image-geometry

It adds a process then call Magick's method to fetch image geometry.

Code:

  version :post do
    process :resize_to_fit => [200, nil]
    process :get_geometry

    def geometry
      @geometry
    end
  end

  def get_geometry
    if (@file)
      img = ::Magick::Image::read(@file.file).first
      @geometry = [ img.columns, img.rows ]
    end
  end

Carrierwave getting image width and height and storing it in an hstore field

Try this

class FileUploader < CarrierWave::Uploader::Base

  # Include RMagick or MiniMagick support:
  include CarrierWave::RMagick
  process :store_geometry, :if => :image?

  #......
  #......
  #......

  def store_geometry
    if image?(@file)
      img = ::Magick::Image::read(@file.file).first
      if model
        model.ImageWidth = img.columns
        model.ImageHeight = img.rows
      end
    end
  end
end

#Hstore

  %w[ImageHeight ImageWidth].each do |key|
    attr_accessible key

    define_method(key) do
      properties && properties[key]
    end

    define_method("#{key}=") do |value|
      self.properties = (properties || {}).merge(key => value)
    end
  end

Assumptions

I'm assuming there's a reason you have the image method that checks if the file is an image, that must mean you're uploading other file formats as well. Well, i've put it to good use here, it calls process_geometry method only if the file is an image.
Hope it helps.

Sending information from image uploader to the model carrierwave

To use some fields only for validations, one can define attr_accessor on the model, but need to keep in mind that these attributes would only be available when assigned explicitly(since not backed by DB columns).

For current scenario, you can keep your current code and define attr_accessor :height, :width on the model and use them in validations.

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