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: [email protected]
  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
     [email protected]

     Glenn W. Parsons
     [email protected]

     James Rafferty
     [email protected]

  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.           |
  +----+---------+-------------------------------------------------+



































McIntyre, et al.            Standards Track                     [Page 6]

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: [email protected] or
         [email protected]


  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: [email protected]


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

  Phone: +1-781-433-9462
  Fax:   +1-781-433-9268
  EMail: [email protected]




















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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.

  This document and the information contained herein are provided on an
  "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
  OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
  ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
  INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
  INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
  WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

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  this standard.  Please address the information to the IETF at ietf-
  [email protected].

Acknowledgement

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







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