Network Working Group Glenn Parsons Internet Draft James Rafferty Expires in six months May 30, 1997 Tag Image File Format (TIFF) - image/TIFF MIME Sub-type Registration Status of this Memo This document is an Internet Draft. 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". To learn the current status of any Internet-Draft, please check the "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast). Overview This document describes the registration of the MIME sub-type image/tiff. The baseline encoding is defined by [TIFF] and a common Internet fax format is defined in [TIFF-F]. 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 . Internet Draft TIFF-F May 30, 1997 1. Abstract This document describes the registration of the MIME sub-type image/tiff. The baseline encoding is defined by [TIFF] and a common Internet fax format is defined in [TIFF-F]. This document refines an earlier sub-type registration in RFC 1528 [TPC.INT]. 2. TIFF Definition TIFF (Tag Image File Format) Revision 6.0 is defined in detail by Adobe in [TIFF]. The documentation can be obtained from Adobe at: Adobe Developers Association Adobe Systems Incorporated 345 Park Avenue San Jose, CA 95110-2704 Phone: +1-408-536-6000 Fax: +1-408-537-6000 A copy of this specification can also be found in: ftp://ftp.adobe.com/pub/adobe/devrelations/devtechnotes/pdffiles/tif f6.pdf 2.1 TIFF-F Definition Though it has been in common usage for many years, TIFF-F has previously never been documented in the form of a standard. An informal TIFF-F document was originally created by a small group of fax experts led by Joe Campbell. The existence of TIFF-F is noted in [TIFF] but it is not defined. The formal definition for TIFF-F for Internet applications can be found in [TIFF-F]. 3. MIME Definition 3.1 image/TIFF The image/TIFF sub-type was originally defined in RFC 1528 as containing TIFF 5.0 encoded image data. This document re-defines the original image/TIFF definition to refer to TIFF 6.0 encoded image data. The TIFF 6.0 specification is a cleaner document and is compatible with previous TIFF 5.0 encoded image data. Parsons, Rafferty Expires 11/30/97 [Page 2] Internet Draft TIFF-F May 30, 1997 3.2 Application parameter Up until TIFF 6.0, TIFF supported various "Classes" which defined the use of TIFF for various applications. The intent of Classes had been to reduce the information burden on TIFF readers and writers that wished to support narrow applications. There are it cases where it may be useful to identify the application applicable to the content of an image/TIFF body. As a result, an optional "application" parameter is defined for image/TIFF to identify the TIFF application of the encoded image data, if it is known. TIFF-F [TIFF-F] has been known historically as "TIFF Class F" and previous informal TIFF-F documents used this terminology. This document defines the application parameter value "F" to correspond to a bi-level facsimile image defined by [TIFF-F]. Example: Content-type: image/TIFF; application=F There is no default value for application, as the absence of the application parameter indicates that the encoded TIFF image is Baseline TIFF or that it is not necessary to identify the application. It is up to the implementation to determine the application (if necessary) and present the image to the user. 3.3 Interoperability considerations The ability of implementations to handle all the defined applications of TIFF may not be ubiquitous. As a result, the absence of the application parameter would force implementations to decode and attempt to display the encoded TIFF image data in order to determine if it could actually be viewed. 4. IANA Registration To: ietf-types@iana.org Subject: Registration of Standard MIME media type image/TIFF MIME media type name: image MIME subtype name: TIFF Required parameters: none Parsons, Rafferty Expires 11/30/97 [Page 3] Internet Draft TIFF-F May 30, 1997 Optional parameters: application The applications of TIFF are denoted by letters. A single application is defined here for TIFF-F as follows: F - Bi-Level Facsimile There is no default value for application, as the absence of the application parameter indicates that the encoded TIFF image is Baseline TIFF or that it is not necessary to identify the application. It is up to the implementation to determine the application (if necessary) and present the image to the user. Encoding considerations: Binary or Base-64 generally preferred Security considerations: none Interoperability considerations: The ability of implementations to handle all the defined applications of TIFF may not be ubiquitous. As a result, the absence of the application parameter would force implementations to decode and attempt to display the encoded TIFF image data in order to determine if it could actually be viewed. Published specification: TIFF (Tag Image File Format) is defined in: TIFF (TM) Revision 6.0 - Final - June 3, 1992 Adobe Developers Association Adobe Systems Incorporated 345 Park Avenue San Jose, CA 95110-2704 Phone: +1-408-536-6000 Fax: +1-408-537-6000 A copy of this specification can be found in: ftp://ftp.adobe.com/pub/adobe/devrelations/devtechnotes/pdff iles/tiff6.pdf TIFF-F is defined in [TIFF-F] Applications which use this media type: primarily fax and voice messaging Additional information: Magic number(s): II (little-endian): 49 49 42 00 hex MM (big-endian): 4D 4D 00 42 hex File extension(s): .TIF Macintosh File Type Code(s): TIFF Parsons, Rafferty Expires 11/30/97 [Page 4] Internet Draft TIFF-F May 30, 1997 Person & email address to contact for further information: Glenn W. Parsons Glenn.Parsons@Nortel.ca James Rafferty Jrafferty@worldnet.att.net Intended usage: COMMON Author/Change controller: James Rafferty 5. Authors' Addresses Glenn W. Parsons Nortel Technology P.O. Box 3511, Station C Ottawa, ON K1Y 4H7 Canada Phone: +1-613-763-7582 Fax: +1-613-763-8385 Email: Glenn.Parsons@Nortel.ca James Rafferty Human Communications 12 Kevin Drive Danbury, CT 06811-2901 USA Phone: +1-203-746-4367 Fax: +1-203-746-4367 Email: Jrafferty@worldnet.att.net 6. References [MIME4] N. Freed and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures", RFC 2048, Innosoft, First Virtual, Nov 1996. [TIFF] Adobe Developers Association, TIFF (TM) Revision 6.0 - Final, June 3, 1992. [TIFF-F] G. Parsons and J. Rafferty, " Tag Image File Format (TIFF) - Application F", Work In Progress, , May 1997. [TPC.INT] C. Malamud, M. Rose, "Principles of Operation for the TPC.INT Subdomain: Remote Printing -- Technical Procedures", RFC 1528, 10/06/1993 Parsons, Rafferty Expires 11/30/97 [Page 5]