You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: thumbnail.rb
    path of file: ./repos/muvee/app/models
    
    the code of the file until where you have to start completion: #require 'phash/image' # temporarily disabled

class Thumbnail < ActiveRecord::Base
  belongs_to :video
  before_destroy :destroy_thumbnail_file
  after_create :postprocess_thumbnail

  IDEAL_NUMBER_OF_THUMBNAILS = 10
  THUMBNAIL_FOLDER = Rails.root.join('public', 'thumbnails')

  def url
    "/thumbnails/#{File.basename(raw_file_path)}"
  end

  def check_for_sbs_3d(opts = {})
    return false # temporarily disabled
    lhs = MiniMagick::Image.open(thumbnail_path)
    rhs = MiniMagick::Image.open(thumbnail_path)
    w = lhs[:width]
    h = lhs[:height]
    half_w = (w/2).to_i

    # http://www.imagemagick.org/script/command-line-processing.php#geometry
    lhs.crop "#{half_w}x#{h}+0+0"
    rhs.crop "#{half_w}x#{h}+#{half_w}+0"
    lhs_output
    
  def check_for_sbs_3d(opts = {})
    return false # temporarily disabled
    lhs = MiniMagick::Image.open(thumbnail_path)
    rhs = MiniMagick::Image.open(thumbnail_path)
    w = lhs[:width]
    h = lhs[:height]
    half_w = (w/2).to_i

    # http://www.imagemagick.org/script/command-line-processing.php#geometry
    lhs.crop "#{half_w}x#{h}+0+0"
    rhs.crop "#{half_w}x#{h}+#{half_w}+0"
    lhs_output = Rails.root.join("tmp", "lhs.jpg")
    rhs_output = Rails.root.join("tmp", "rhs.jpg")
    lhs.write lhs_output
    rhs.write rhs_output

    lhs_small = Rails.root.join("tmp", "lhs-small.jpg")
    rhs_small = Rails.root.join("tmp", "rhs-small.jpg")
    lhs.scale "10%x10%"
    rhs.scale "10%x10%"
    lhs.write lhs_small
    rhs.write rhs_small

    similarity = Phash::Image.new(lhs_small) % Phash::Image.new(rhs_small)
    if similarity > 0.8 # 3D
      if opts[:overwrite]
        result = MiniMagick::Image.open(lhs_output)
        result.scale "200%x100%"
        result.write scaled_path
        FileUtils.copy(scaled_path, thumbnail_path)
      end