INTERNET-DRAFT L. McIntyre Fax Working Group G. Parsons June 24, 2004 Nortel Networks Document: J. Rafferty Brooktrout Technology June 2004 Tag Image File Format Fax eXtended (TIFF-FX) - image/tiff-fx MIME Sub-type Registration Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet Drafts are valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet Drafts as reference material or to cite them other than as a "work in progress". The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. 1. 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. 2. 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]. McIntyre, et. al. Expires December 2004 [Page 1] Internet Draft image/tiff-fx June 2004 3. 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. This document is a product of the IETF Internet Fax Working Group. 4. TIFF-FX Definition TIFF-FX (Tag Image File Format Fax eXtended), is defined in detail by draft-ietf-fax-tiff-fx-13.txt "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. 4.1 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. 4.2 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. McIntyre, et. al. Expires December 2004 [Page 2] Internet Draft image/tiff-fx June 2004 - 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. 5. 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. 6. 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. McIntyre, et. al. Expires December 2004 [Page 3] Internet Draft image/tiff-fx June 2004 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. 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: draft-ietf-fax-tiff-fx-13.txt "File Format for Internet Fax", June 2004, 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 lloyd10328@pacbell.net Glenn W. Parsons gparsons@nortelnetworks.com James Rafferty jraff@brooktrout.com McIntyre, et. al. Expires December 2004 [Page 4] Internet Draft image/tiff-fx June 2004 Intended usage: COMMON Change controller: Lloyd McIntyre 7. 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. 8. 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] Buckley, R., Venable, D., McIntyre, L., Parsons, G., and J. Rafferty, "File Format for Internet Fax", draft-ietf-fax-tiff-fx-13.txt, June 2004. McIntyre, et. al. Expires December 2004 [Page 5] Internet Draft image/tiff-fx June 2004 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. | +----+---------+-------------------------------------------------+ Authors' Addresses Lloyd McIntyre Xerox Corporation 10328 South Stelling Road Cupertino, CA 95014 USA Phone: +1-408 725 1624 Fax: +1-408 725 1624 EMail: lloyd10328@pacbell.net 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. Expires December 2004 [Page 6] Internet Draft image/tiff-fx June 2004 Full Copyright Statement Copyright (C) The Internet Society (2004). 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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Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf- ipr@ietf.org. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. McIntyre, et. al. Expires December 2004 [Page 7]