





Network Working Group                                        L. McIntyre
Request for Comments: 3950                                    Consultant
Obsoletes: 3250                                               G. Parsons
Category: Standards Track                                Nortel Networks
                                                             J. Rafferty
                                                   Brooktrout Technology
                                                           February 2005


      Tag Image File Format Fax eXtended (TIFF-FX) - image/tiff-fx
                       MIME Sub-type Registration

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract

   This document describes the registration of the MIME sub-type
   image/tiff-fx.  The encodings are defined by File Format for Internet
   Fax and its extensions.

1.  Introduction

   This document describes the registration of the MIME sub-type
   image/tiff-fx.  The encodings are defined by File Format for Internet
   Fax [TIFF-FX] and its extensions.

   This document is a product of the IETF Internet Fax Working Group.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in BCP 14, RFC 2119
   [REQ].

2.  TIFF-FX Definition

   Tag Image File Format Fax eXtended (TIFF-FX), is defined in detail by
   RFC 3949, "File Format for Internet Fax" [TIFF-FX].




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RFC 3950                     image/tiff-fx                 February 2005


   While a brief scope and feature description is provided in this
   section as background information, the reader is directed to the
   original TIFF-FX specification (File Format for Internet Fax) to
   obtain complete feature and technical details.

2.1.  TIFF-FX Scope

   This document defines a TIFF-based file format specification for
   enabling standardized messaging-based fax over the Internet.  It
   specifies the TIFF fields and field values required for compatibility
   with the existing ITU-T Recommendations for Group 3 black-and-white,
   grayscale and color facsimile.  TIFF has historically been used for
   handling fax image files in applications such as store-and-forward
   messaging.  Implementations that support this file format
   specification for import/export may elect to support it as a native
   format.  This document recommends a TIFF file structure that is
   compatible with low-memory and page-level streaming implementations.

   Unless otherwise noted, the current TIFF specification [TIFF] and
   selected TIFF Technical Notes [TTN1, TTN2] are the primary references
   for describing TIFF and defining TIFF fields.  This document is the
   primary reference for defining TIFF field values for fax
   applications.

2.2.  TIFF-FX Features

   Some of the features of TIFF-FX are:

   -  TIFF-FX is capable of describing bilevel, grayscale, palette-
      color, full-color and mixed content image data.

   -  TIFF-FX includes a number of compression schemes that allow
      developers to choose the best space or time tradeoff for their
      applications.

   -  TIFF-FX is designed to be extensible and to evolve gracefully as
      new needs arise.

3.  MIME Definition

   This document defines the image/tiff-fx MIME sub-type to refer to
   TIFF-FX Profiles J, C, L and M encoded image data and any future
   TIFF-FX extensions, or a subset.  The image/tiff-fx content type MAY
   be used when black-and-white image data is encoded using TIFF-FX
   Profiles S or F, or a subset, however, the image/tiff content type
   SHOULD be used.





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RFC 3950                     image/tiff-fx                 February 2005


4.  IANA Registration

   To: ietf-types@iana.org
   Subject: Registration of Standard MIME media type image/tiff-fx

   MIME media type name: image

   MIME subtype name: tiff-fx

   Required parameters: none

   Optional parameters: none

   Encoding Considerations:

      This media type consists of binary data.  The base64 encoding
      should be used on transports that cannot accommodate binary data
      directly.

   Security considerations:

      TIFF-FX utilizes a structure which can store image data and
      attributes of this image data.  The fields defined in the TIFF-FX
      specification are of a descriptive nature and provide information
      that is useful to facilitate viewing and rendering of images by a
      recipient.  As such, the fields currently defined in the TIFF-FX
      specification do not in themselves create additional security
      risks, since the fields are not used to induce any particular
      behavior by the recipient application.

      TIFF-FX has an extensible structure, so that it is theoretically
      possible that fields could be defined in the future which could be
      used to induce particular actions on the part of the recipient,
      thus presenting additional security risks, but this type of
      capability is not supported in the referenced TIFF-FX
      specification.  Indeed, the definition of fields which would
      include such processing instructions is inconsistent with the
      goals and spirit of the TIFF-FX specification.

      The MIME type and file extension defined by this document MUST NOT
      be used to blindly select a processing program.  It is up to the
      implementation to determine the application (if necessary) and
      render the image to the user.








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RFC 3950                     image/tiff-fx                 February 2005


   Interoperability considerations:

      The ability of implementations to handle all the defined
      applications (or profiles within applications) of TIFF-FX may not
      be ubiquitous.  As a result, implementations may decode and
      attempt to display the encoded TIFF-FX image data only to
      determine that the image cannot be rendered.

   Published specification:

      TIFF-FX (Tag Image File Format Fax eXtended) is defined in:

      RFC 3949, "File Format for Internet Fax", February 2005, Buckley,
      R., Venable, D., McIntyre, L., Parsons, G., and J. Rafferty.

   Applications which use this media type:

      Imaging, fax, messaging and multi-media

   Additional information:

      Magic number(s):
           II (little-endian):  49 49 2A 00 hex
           MM (big-endian):     4D 4D 00 2A hex
      File extension(s): .TFX
      Macintosh File Type Code(s): TFX

   Person & email address to contact for further information:

      Lloyd McIntyre
      Lloyd_McIntyre@Dell.com

      Glenn W. Parsons
      gparsons@nortelnetworks.com

      James Rafferty
      jraff@brooktrout.com

   Intended usage: COMMON

   Change controller: Lloyd McIntyre










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RFC 3950                     image/tiff-fx                 February 2005


5.  Security Considerations

   TIFF-FX utilizes a structure which can store image data and
   attributes of this image data.  The fields defined in the TIFF-FX
   specification are of a descriptive nature and provide information
   that is useful to facilitate viewing and rendering of images by a
   recipient.  As such, the fields currently defined in the TIFF-FX
   specification do not in themselves create additional security risks,
   since the fields are not used to induce any particular behavior by
   the recipient application.

   TIFF-FX has an extensible structure, so that it is theoretically
   possible that fields could be defined in the future which could be
   used to induce particular actions on the part of the recipient, thus
   presenting additional security risks, but this type of capability is
   not supported in the referenced TIFF-FX specification.  Indeed, the
   definition of fields which would include such processing instructions
   is inconsistent with the goals and spirit of the TIFF-FX
   specification.

   The MIME type and file extension defined by this document MUST NOT be
   used to blindly select a processing program.  It is up to the
   implementation to determine the application (if necessary) and render
   the image to the user.

6.  References

6.1.  Normative References

   [TIFF-FX] Buckley, R., Venable, D., McIntyre, L., Parsons, G., and J.
             Rafferty, "File Format for Internet Fax", RFC 3949,
             February 2005.

6.2.  Informative References

   [TIFF]    Adobe Developers Association, TIFF (TM) Revision 6.0 -
             Final, June 3, 1992.

   [REQ]     Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.

   [TTN1]    Adobe PageMaker 6.0 TIFF Technical Notes, Sept. 14, 1995,
             http://partners.adobe.com/asn/developer/pdfs/tn/TIFFPM6.pdf

   [TTN2]    Adobe Photoshop TIFF Technical Notes, Replacement TIFF/JPEG
             specification, March 22, 2002,
             http://partners.adobe.com/asn/developer/pdfs/tn/
             TIFFphotoshop.pdf



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RFC 3950                     image/tiff-fx                 February 2005


Annex A. List of edits to RFC 3250

   +----+---------+-------------------------------------------------+
   | No.| Section |                  Edit                           |
   +----+---------+-------------------------------------------------+
   | 1. | All     | Updated references from RFC 2301 to             |
   |    |         | draft-ietf-fax-tiff-fx-13.txt                   |
   +----+---------+-------------------------------------------------+
   | 2. | 5       | MIME Definition - added a "SHOULD" statement to |
   |    |         | stress that image/tiff is the preferred content |
   |    |         | type when representing Profiles S and/or F.     |
   +----+---------+-------------------------------------------------+
   | 3. | 7       | Revise security considerations.                 |
   +----+---------+-------------------------------------------------+
   | 4. | 3       | Merged sections 2 & 3 and renumbered.           |
   +----+---------+-------------------------------------------------+



































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RFC 3950                     image/tiff-fx                 February 2005


Authors' Addresses

   Lloyd McIntyre
   10328 S. Stelling Road
   Cupertino, CA 95014 USA

   Phone: +1-408-725-1624
   EMail: lloyd10328@pacbell.net or
          Lloyd_McIntyre@Dell.com


   Glenn W. Parsons
   Nortel Networks
   P.O. Box 3511, Station C
   Ottawa, ON  K1Y 4H7
   Canada

   Phone: +1-613-763-7582
   Fax:   +1-613-967-5060
   EMail: gparsons@nortel.com


   James Rafferty
   Brooktrout Technology
   410 First Avenue
   Needham, MA  02494
   USA

   Phone: +1-781-433-9462
   Fax:   +1-781-433-9268
   EMail: jraff@brooktrout.com




















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RFC 3950                     image/tiff-fx                 February 2005


Full Copyright Statement

   Copyright (C) The Internet Society (2005).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

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   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
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Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.







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