to_hash method does not work

[jedrekdomanski]

require 'exifr'
include EXIFR

unless ARGV[0] and File.exists?(ARGV[0])
puts "You need to give a name: imageInfo.rb \n\n"
exit
end
info = JPEG.new(ARGV[0])
File.open("info_#{File.basename(ARGV[0])}.txt", "w") do |output|
output.puts info.exif.to_hash.map{ |k,v| "#{k}: #{v}" }
end

undefined method `to_hash' for nil:NilClass (NoMethodError)

What's wrong?

[remvee]

The #exif methods returns nil when the JPEG does not contain EXIF data.