Pentax RAW file to jpeg, preserving creation date

raw-to-jpg.rb

filename = ARGV[0]
raise "specify PEF file." unless filename =~ /.PEF$/ # should change according to what you want to convert
raise "file #{filename} does not exists." unless File.exist?(filename)
stat = File::Stat.new(filename)
converted = filename.sub(/.PEF$/, ".jpg")

raise "convesion failed" unless system "convert #{filename} #{converted}"
File.utime(stat.mtime, stat.mtime, converted)