Network Working Group Glenn Parsons Internet Draft James Rafferty Expires in six months Stephen Zilles December 22, 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]. 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 image/tiff December 22, 1997 1. Abstract This document describes the registration of the MIME sub-type image/tiff. The baseline encoding is defined by [TIFF]. 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/ tiff6.pdf While a brief scope and feature description is provided in this section as background information, the reader is directed to the original TIFF specification [TIFF] to obtain complete feature and technical details. 2.1 TIFF Scope TIFF describes image data that typically comes from scanners, frame grabbers, and paint- and photo-retouching programs. TIFF is not a printer language or page description language. The purpose of TIFF is to describe and store raster image data. A primary goal of TIFF is to provide a rich environment within which applications can exchange image data. This richness is required to take advantage of the varying capabilities of scanners and other imaging devices. Though TIFF is a rich format, it can easily be used for simple scanners and applications as well because the number of required fields is small. 2.2 TIFF Features Some of the features of TIFF (from [TIFF]) are: - TIFF is capable of describing bilevel, grayscale, palette-color, and full-color image data in several color spaces. Parsons, Rafferty, Zilles Expires 06/22/98 [Page 2] Internet Draft image/tiff December 22, 1997 - TIFF includes a number of compression schemes that allow developers to choose the best space or time tradeoff for their applications. - TIFF is designed to be extensible and to evolve gracefully as new needs arise. - TIFF allows the inclusion of an unlimited amount of private or special-purpose information. 3. MIME Definition 3.1 image/tiff The image/tiff content-type was previously defined in RFC 1528 as containing TIFF 6.0 encoded image data. This document re-defines the original image/tiff definition to refer to TIFF 6.0 [TIFF] encoded image data, but with a revised reference (section 2) and a new parameter (section 3.2). 3.2 Application parameter There are cases where it may be useful to identify the application applicable to the content of an image/tiff body. Typically, this would be used to assist the recipient in dispatching a suitable rendering package to handle the display or processing of the image file. As a result, an optional "application" parameter is defined for image/tiff to identify a particular application's subset of TIFF and TIFF extensions for the encoded image data, if it is known. No values are defined in this document. Example: Content-type: image/tiff; application=foo 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 recipient's implementation to determine the application (if necessary) and render the image to the user. 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 Parsons, Rafferty, Zilles Expires 06/22/98 [Page 3] Internet Draft image/tiff December 22, 1997 Required parameters: none Optional parameters: application There is no format specified for the value of this parameter in addition to that specified by [MIME1]. Various applications of TIFF may define values as required. 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 render 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 (or profiles within applications) of TIFF may not be ubiquitous. As a result, implementations may decode and attempt to display the encoded TIFF image data only to determine that the image cannot be rendered. The presence of the application parameter may aid in allowing this determination before dispatching for rendering. However, it should be noted that the parameter value is not intended to convey levels of capabilities for a particular application. 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 Applications which use this media type: Imaging, fax, messaging and multi-media Parsons, Rafferty, Zilles Expires 06/22/98 [Page 4] Internet Draft image/tiff December 22, 1997 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 Person & email address to contact for further information: Glenn W. Parsons Glenn.Parsons@Nortel.ca James Rafferty Jrafferty@worldnet.att.net Stephen Zilles szilles@adobe.com Intended usage: COMMON Change controller: Stephen Zilles 5. Authors' Addresses Glenn W. Parsons Northern Telecom P.O. Box 3511, Station C Ottawa, ON K1Y 4H7 Canada Phone: +1-613-763-7582 Fax: +1-613-763-2697 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 Parsons, Rafferty, Zilles Expires 06/22/98 [Page 5] Internet Draft image/tiff December 22, 1997 Stephen Zilles Adobe Systems Inc. Mailstop W14 345 Park Avenue San Jose, CA 95110-2704 USA Voice: +1-408-536-4766 Fax: +1-408-536-4042 Email: szilles@adobe.com 6. References [MIME1] N. Freed and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, Innosoft, First Virtual, Nov 1996 [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. [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, Zilles Expires 06/22/98 [Page 6]