From: Ollivier Robert <ollivier.robert@...>
Date: 2008-01-03T18:55:01+09:00
Subject: Re: RMagick Exif

In article <3ed10879dcc030dbf9b38fb1b5575955@ruby-forum.com>,
John Smith  <john.smith@sherwoodmechanical.com> wrote:
>I have been working to extract the exif information from jpegs using
>RMagick and the get_exif_by_entry function.  However, no matter what I
>try it returns an empty array.  I am certain the file has exif info as I
>save it from Photoshop with the embed XMP option selected.

The way I deal with these is by using exiftool with the mini_exiftool Ruby module.  It has been working great so far.

-----
require "rubygems"
require "mini_exiftool"
[...]
def set_lens_info(data)
  lens_type = data.lens_type
  #
  # Check for M-42 lens
  #
  if lens_type.nil? or lens_type =~ /M-42|K,M/ then
[...]
  data.lens_type = lens_type
  data.save
end # -- set_lens_info
[...]
def main(argv)
  argv.each do |fn|
    data = MiniExiftool.new(fn)
    ts = data.date_time_original
    save_ok = set_lens_info(data)
    if save_ok then
      File.utime(Time.now, ts, fn)
      STDERR.puts("#{fn} saved ok, time changed")
      STDERR.puts("  #{data.lens}")
    else
      STDERR.puts("Error saving #{fn}")
      data.errors.each do |fld, msg|
        STDERR.puts("  #{fld}: #{msg}")
      end
    end
  end
  return 0
end # -- main


-- 
Ollivier ROBERT -=- EEC/RIF/SEU -=-
Systems Engineering Unit