IFX Mail Archive: MOD - Confusion about image/tiff MIME Content Type

IFX Mail Archive: MOD - Confusion about image/tiff MIME Content Type

MOD - Confusion about image/tiff MIME Content Type

Hastings, Tom N (hastings@cp10.es.xerox.com)
Thu, 18 Feb 1999 08:52:04 -0800

I'm confused and concerned about what the MIME Content Type 'image/tiff'
means and implies.

There is the IANA Registration from 1993 and there is RFC 2301 File Format
for Internet Fax. RFC 2301 seems to define a lot more than the original
'image/tiff'. Worse, the IANA registration entry does not cite RFC 2301.

IPP uses MIME Content Types (MIME Media Types?) to indicate the format of a
document in a create job request (the "document-format" Job object
attribute) and for an IPP Printer to indicate what document formats it is
capable of printing (the "document-format-supported" Printer object
attribute).

Should the IPP mimeMediaType value in [ipp-mod] section 4.1.9 be listed as:

'image/tiff': Tag Image Format - see IANA MIME Media Type registry

or:

'image/tiff': Tag Image Format - see File Format for Internet Fax
[RFC2301]

or:

'image/tiff': Tag Image Format - see IANA MIME Media Type registry
and [RFC2301]

Thanks,
Tom

The IANA Registration for image/tiff MIME Media Type is:

To: iana@ISI.EDU
Subject: Registration of new MIME content-type/subtype
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Date: Sat, 31 Jul 1993 20:04:00 -0700
From: Marshall Rose <mrose@dbc.mtview.ca.us>
Content-Length: 491
Status: RO
X-Lines: 24

MIME type name: image

MIME subtype name: tiff

Required parameters: none

Optional parameters: none

Encoding considerations: base64

Security considerations: none

Published specification: TIFF class F, as defined in:

Tag Image File Format (TIFF) revision 6.0

Developer's Desk Aldus Corporation
411 First Ave. South Suite
200 Seattle, WA 98104
206-622-5500

or:

Tile Format for Internet Fax
<draft-ietf-fax-tiffplus-07.txt>

Person & email address to contact for further information:

Glenn Parsons <Glenn.Parsons@Nortel.ca>

On the other hand a March 1998 RFC entitled "File Format For Internet FAX"
formally defines TIFF/FX as minimal, extended and lossless JBIG modes
(Profiles S, F, J) for black-and-white fax, and base JPEG, lossless JBIG and
Mixed Raster Content modes (Profiles C, L, M) for color and grayscale fax.
These modes or profiles correspond to the content of the applicable ITU-T
Recommendations. Files formatted according to this specification use the
image/tiff MIME Content Type.

So if an IPP Printer's "document-format-supported" attribute includes the
MIME Content Type (or is it MIME Media Type?) with a value of 'image/tiff',
does that mean that the IPP Printer supports all of the above
representations? If so, how come the IANA registered MIME media type
doesn't mention RFC 2301?

ISSUE: Should IPP refer to the IANA registration of 'image/tiff' or to RFC
2301 as the definition of what the 'image/tiff' value means in the
"document-format" attribute that a client can supply in a create job request
and that a Printer object uses to indicate the document formats that it is
capable of accepting and printing?

Here is the Abstract for RFC 2301:

Network Working Group L. McIntyre
Request for Comments: 2301 Xerox Corporation
Category: Standards Track S. Zilles
Adobe Systems, Inc.
R. Buckley
Xerox Corporation
D. Venable
Xerox Corporation
G. Parsons
Northern Telecom
J. Rafferty
Human Communications
March 1998
File Format for Internet Fax

Abstract

This document describes the TIFF (Tag Image File Format)
representation of image data specified by the ITU-T Recommendations
for black-and-white and color facsimile. This file format
specification is commonly known as TIFF-FX. It formally defines
minimal, extended and lossless JBIG modes (Profiles S, F, J) for
black-and-white fax, and base JPEG, lossless JBIG and Mixed Raster
Content modes (Profiles C, L, M) for color and grayscale fax. These
modes or profiles correspond to the content of the applicable ITU-T
Recommendations. Files formatted according to this specification use
the image/tiff MIME Content Type.

Tom Hastings
(310) 333-6413