nef2jpg.rb

#!/usr/bin/env ruby
# encoding: utf-8

# Usage:
# nef2jpg.rb DSC_5069.NEF
# nef2jpg.rb DSC_50??.NEF
# nef2jpg.rb .

# settings
PROCESSES = 4
NICE = 20
UFRAW_ARGUMENTS = {
  wb: "camera",
  exposure: "auto",
  saturation: "auto",
  black_point: "auto",
  compression: 85,
  out_type: "jpg",
  silent: true
}

# assertions
abort "Did you backed up your photos?!"

# case NICE
# when (-20..-10), (10..20)
#   warn "You set NICE to #{NICE}, but this value requires root permissions. Re-running with sudo ..."
#   exec "sudo #{$0} #{ARGV.map { |path| '#{path}' }.join(" ")}"
# else
#   abort "NICE can't be #{NICE}!"
# end

# helpers
def UFRAW_ARGUMENTS.to_arguments
  self.inject(Array.new) do |buffer, pair|
    key, value = pair
    key = key.to_s.gsub("_", "-")
    if pair.last.eql?(true)
      buffer << "--#{key}"
    elsif pair.last.eql?(false)
      buffer << "--no#{key}"
    else
      buffer << "--#{key}=#{value}"
    end
  end.join(" ")
end

# Expand directories in ARGV to list of files.
# This is NOT recursive.
files = ARGV.inject(Array.new) do |buffer, path|
  if File.directory?(path)
    files = Dir.glob("#{path}/*.NEF")
    buffer.unshift(*files)
  else
    buffer << path
  end
end

n = files.length / PROCESSES
queues = Array.new

until files.empty?
  queues << files.slice!(0..n)
end

# We really need to utilize multiple processors,
# but the GIL in Ruby basically makes threads kind
# of useless, so let's run multiple processes.
queues.each do |queue|
  fork do
    files = queue.map { |path| "'#{path}'" }
    arguments = UFRAW_ARGUMENTS.to_arguments
    # command = "nice -n #{NICE} ufraw-batch #{arguments} #{files.join(" ")}" # ufraw-batch do some weird stripe
    # command = "nice -n #{NICE} dcraw #{files.join(" ")}"

    command = files.inject(String.new) do |buffer, file|
      buffer += "nice -n #{NICE} dcraw #{file}"
      buffer += "; convert #{file.sub(/\.NEF/, ".ppm")} #{file.sub(/\.NEF/, ".jpg")}"
      buffer += "; rm #{file.sub(/\.NEF/, ".ppm")}"
    end

    puts command
    system command
  end
end

Process.waitall