Correct the creationtime of photos based on EXIF data.

update_ctime.rb

require 'exifr'

files = Dir['**/*']

files.each do |file|
  if File.file?(file) && File.extname(file).downcase == '.jpg'
    begin
      exif = EXIFR::JPEG.new(file)
      if !exif.date_time_original.nil?
        File.utime(exif.date_time_original, exif.date_time_original, file)
      end
    rescue
      puts "#{file} - #{$!}"
    end
  end
end