Image cropper error using carrier wave

Error in log

CarrierWave::ProcessingError (Failed to manipulate with MiniMagick, maybe it is not an image? Original Error: Command ("mogrify -crop '217x217+0+136' /var/folders/1_/fj3rk_750w32l91pxp59xz180000gn/T/mini_magick20130913-12950-ul75bn.jpg") failed: {:status_code=>1, :output=>"mogrify: invalid argument for option `'217x217+0+136'': -crop @ error/mogrify.c/MogrifyImageCommand/4227.\n"}):

image_uploader.rb

# encoding: utf-8

class ImageUploader < CarrierWave::Uploader::Base

  # Include RMagick or MiniMagick support:
  # include CarrierWave::RMagick
  include CarrierWave::MiniMagick

  # Include the Sprockets helpers for Rails 3.1+ asset pipeline compatibility:
  include Sprockets::Helpers::RailsHelper
  include Sprockets::Helpers::IsolatedHelper

  # Choose what kind of storage to use for this uploader:
  storage :file
  # storage :fog

  # Override the directory where uploaded files will be stored.
  # This is a sensible default for uploaders that are meant to be mounted:
  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end

  # Provide a default URL as a default if there hasn't been a file uploaded:
  # def default_url
  #   # For Rails 3.1+ asset pipeline compatibility:
  #   # asset_path("fallback/" + [version_name, "default.png"].compact.join('_'))
  #
  #   "/images/fallback/" + [version_name, "default.png"].compact.join('_')
  # end

  # Process files as they are uploaded:
  # process :scale => [200, 300]
  #
  # def scale(width, height)
  #   # do something
  # end

  # Create different versions of your uploaded files:
  # version :thumb do
  #   process :scale => [50, 50]
  # end

  def crop_to
    model.logout "crop_to"
    manipulate! do |img|
      return img unless model.is_croppable?

      model.log(img )

      img = img.crop("'#{model.width}x#{model.height}+#{model.left}+#{model.top}'")
      img = yield(img) if block_given?
      img
    end
  end


  version :favicon do
    process :crop_to
    process resize_to_fill: [16,16]
  end

  version :small do
    process :crop_to
    process resize_to_fill: [32,32]
  end

  version :thumb do
    process :crop_to
    process resize_to_fill: [64,64]
  end

  version :avatar do
    process :crop_to
    process resize_to_fill: [120,120]
  end


  # Add a white list of extensions which are allowed to be uploaded.
  # For images you might use something like this:
  # def extension_white_list
  #   %w(jpg jpeg gif png)
  # end

  def extension_white_list
    %w(jpg jpeg png gif)
  end

  # Override the filename of the uploaded files:
  # Avoid using model.id or version_name here, see uploader/store.rb for details.
  # def filename
  #   "something.jpg" if original_filename
  # end

end