Renames all pictures in the folder using EXIF date/time

rename_photos_by_date.rb

require 'rubygems'
require 'exifr'

data = Dir.glob("photos/*.jpg").collect do |file|
  {
    :file => file,
    :time => EXIFR::JPEG.new(file).date_time,
  }
end

data = data.sort_by { |item| item[:time] }

data.each do |item|
  t = item[:time].strftime("%y%m%d_%H%M%S")
  name = "photos/photo_#{t}.jpg"
  p name
  File.rename(item[:file], name)
end