Request for Comments: 3250
Category: Standards Track
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 © The Internet Society (2002). All Rights Reserved.
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].
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 <email@example.com>.
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: firstname.lastname@example.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.
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 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.
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
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:
Glenn W. Parsons
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.
[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. | +----+---------+-------------------------------------------------+
3400 Hillview Avenue
Palo Alto, CA 94304
Phone: +1-650 813 6762 Fax: +1-650 813 5850 EMail: email@example.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: firstname.lastname@example.org James Rafferty Brooktrout Technology 410 First Avenue Needham, MA 02494 USA Phone: +1-781-433-9462 Fax: +1-781-433-9268 EMail: email@example.com
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