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Network Working Group L. McIntyre
Request for Comments: 3250 Xerox Corporation
Category: Standards Track G. Parsons
Nortel Networks
J. Rafferty
Brooktrout Technology
September 2002
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 (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>.
McIntyre, et. al. Standards Track [Page 1]
RFC 3250 image/tiff-fx September 2002 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. McIntyre, et. al. Standards Track [Page 2]
RFC 3250 image/tiff-fx September 2002 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. McIntyre, et. al. Standards Track [Page 3]
RFC 3250 image/tiff-fx September 2002 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 McIntyre, et. al. Standards Track [Page 4]
RFC 3250 image/tiff-fx September 2002 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. McIntyre, et. al. Standards Track [Page 5]
RFC 3250 image/tiff-fx September 2002 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 McIntyre, et. al. Standards Track [Page 6]
RFC 3250 image/tiff-fx September 2002 Full Copyright Statement Copyright (C) The Internet Society (2002). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. McIntyre, et. al. Standards Track [Page 7]