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 © The Internet Society (2002). All Rights Reserved.

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. Conventions used in this document

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 RFC-2119 [REQ].

2. Overview

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.

3. Internet Fax Working Group

This document is a product of the IETF Internet Fax Working Group. All comments on this document should be forwarded to the email distribution list at <ietf-fax@imc.org>.

3. TIFF-FX Definition

TIFF-FX (Tag Image File Format Fax eXtended), is defined in detail by RFC 2301 "File Format for Internet Fax" [TIFF-FX].

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.

3.1 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.

3.2 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.

4. 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.

5. 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.

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 2301 "File Format for Internet Fax", January 1998
      McIntyre, L., Zilles, S., Buckley, R., Venable, D.,
      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
lmcintyre@xerox.com

Glenn W. Parsons
gparsons@nortelnetworks.com

James Rafferty
jraff@brooktrout.com

   Intended usage: COMMON

Change controller: Lloyd McIntyre

6. Security Considerations

Security issues for this media type are discussed in the security considerations section of the media type registration that appears in section 5.

7. References

   [REQ]     Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.
   
   [MIME1]   Freed, N. and N. Borenstein, "Multipurpose Internet Mail
             Extensions (MIME) Part One: Format of Internet Message
             Bodies", RFC 2045, November 1996.
   
   [MIME4]   Freed, N. and N. Borenstein, "Multipurpose Internet Mail
             Extensions (MIME) Part Four: Registration Procedures", BCP
             13, RFC 2048, November 1996.
   
   [TIFF]    Adobe Developers Association, TIFF (TM) Revision 6.0 -
             Final, June 3, 1992.
   
   [TPC.INT] C. Malamud, M. Rose, "Principles of Operation for the
             TPC.INT Subdomain:  Remote Printing -- Technical
             Procedures", RFC 1528, 10/06/1993
   
   [TIFF-FX] McIntyre, L., Zilles, S., Buckley, R., Venable, D.,
             Parsons, G. and J. Rafferty, "File Format for Internet
             Fax", RFC 2301, January 1998.

Annex A. List of edits to TIFF-FX Registration

   +----+---------+-------------------------------------------------+
   | No.| Section |           Edit Nov. 21, 2000                    |
   +----+---------+-------------------------------------------------+
   | 1. | 7.0     | Corrected Magic Number from 49 49 42 00 hex and |
   |    |         | 4D 4D 00 42 hex to 49 49 2A 00 hex and          |
   |    |         | 4D 4D 00 2A hex respectively.                   |
   +----+---------+-------------------------------------------------+

Authors' Addresses

Lloyd McIntyre
Xerox Corporation
3400 Hillview Avenue
Palo Alto, CA 94304
USA

   Phone: +1-650 813 6762
   Fax:   +1-650 813 5850
   EMail: lmcintyre@pahv.xerox.com
   
   Glenn W. Parsons
   Nortel Networks
   P.O. Box 3511, Station C
   Ottawa, ON  K1Y 4H7
   Canada
   
   Phone: +1-613-763-7582
   Fax:   +1-613-763-2697
   EMail: gparsons@nortelnetworks.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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