Fax working group                                       Lloyd McIntyre
INTERNET-DRAFT                                       Xerox Corporation
Category: Work-in-progress                                Graham Klyne
                                            5GM/Content Technology Ltd
                                                        September 1998
                                                   Expires: March 1999


               Content feature schema for Internet fax
                <draft-ietf-fax-feature-schema-00.txt>


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 draft documents 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 ``work in
  progress''.

  To view the entire list of current Internet-Drafts, please check
  the "1id-abstracts.txt" listing contained in the Internet-Drafts
  Shadow Directories on ftp.is.co.za (Africa), ftp.nordu.net
  (Northern Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au
  (Pacific Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US
  West Coast).

  [[INTENDED STATUS:  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 Notice

  Copyright (C) The Internet Society 1998.  All Rights Reserved.

Abstract

  This document defines a content feature schema that is a profile of
  the media feature registration mechanisms [1,2,3] for use in
  performing capability identification between extended Internet fax
  systems [5].




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  This document does not describe any specific mechanisms for
  communicating capability information, but does presume that any
  such mechanisms will transfer textual values.  It specifies a
  textual format to be used for describing Internet fax capability
  information.

Table of contents

  1. Introduction ............................................3
     1.1 Organization of this document                        3
     1.2 Terminology and document conventions                 3
     1.3 Revision history                                     4
     1.4 Unfinished business                                  4
  2. Fax feature schema syntax ...............................4
  3. Internet fax feature tags ...............................4
     3.1 Image Size                                           5
     3.2 Resolution                                           5
     3.3 Media type                                           5
     3.4 Paper Size                                           6
     3.5 Color and greyscale                                  6
     3.6 Coding                                               7
     3.7 Color model                                          7
     3.8 Preferred units                                      7
  4. Examples ................................................7
     4.1 Simple fax machine                                   8
     4.2 Grey-scale fax machine                               8
     4.3 Full-colour fax machine                              8
     4.4 PC-based e-mail recipient                            8
  5. Security considerations .................................8
  6. Full copyright statement ................................8
  7. Acknowledgements ........................................8
  8. References ..............................................9
  9. Authors' addresses ......................................10
  Appendix A: Feature registrations ..........................10


1. Introduction

  This document defines a content feature schema that is a profile of
  the media feature registration mechanisms [1,2,3] for use in
  performing capability identification between extended Internet fax
  systems [5].

  This document does not describe any specific mechanisms for
  communicating capability information, but does presume that any
  such mechanisms will transfer textual values.  It specifies a
  textual format to be used for describing Internet fax capability
  information.

  The range of capabilities that can be indicated are based on those
  defined for Group 3 facsimile [6].  A companion document [4]


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  describes the relationship and mapping between this schema and
  Group 3 fax capabilities.

1.1 Organization of this document

  Section 2 specifies the overall syntax for fax feature descriptions
  by reference to the media feature registration and syntax documents
  [1,2].

  Section 3 enumerates the feature tags that MUST be recognized and
  processed by extended Internet fax systems, according to their
  capabilities.

  Appendix A contains additional feature tag registrations for media
  features that are specific to fax and for which no applicable
  registration already exists.  These are presented in the form
  prescribed by the media feature registration procedure [1].

1.2 Terminology and document conventions

  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 [RFC2119].

  The term "eifax system" is used to describe any software, device or
  combination of these that conforms to the specification "Extended
  Facsimile Using Internet Mail" [5].

       NOTE:  Comments like this provide additional nonessential
       information about the rationale behind this document.
       Such information is not needed for building a conformant
       implementation, but may help those who wish to understand
       the design in greater depth.

1.3 Revision history

  00a  28-Sep-1998  Initial draft.

1.4 Unfinished business

  .  Review terminology (especially eifax).

  .  Finalize feature set

  .  Supply examples

  .  Supply new feature registrations






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2. Fax feature schema syntax

  The syntax for the fax feature schema is described by "An algebra
  for describing media feature sets" [2].  This in turn calls upon
  media feature tags that may be registered according to the
  procedure described in "Media Feature Tag Registration Procedure"
  [1].

       ??Note:  The document name for [2] will change to "A
       syntax for describing media feature sets".

       Note:  Media feature registration provides a base
       vocabulary of features that correspond to media handling
       capabilities.  The feature set syntax provides a
       mechanism and format for combining these to describe
       combinations of features that may be handled by eifax
       systems.

3. Internet fax feature tags

  This section enumerates and briefly describes the feature tags that
  MUST be recognized and processed by eifax systems and for which a
  value SHOULD be offered in any capability announcement, according
  to their capabilities.

  That is, a number of feature tags are presented below that an eifax
  system is expected to be able to recognize its ability or non-
  ability to handle.

  Definitive descriptions of feature tags are indicated by reference
  to their registration per the 'conneg' registration procedure (some
  of which are appended to this document)

       NOTE:  The presence of a feature tag in this list does
       not mean that an eifax system must have that capability;
       rather, it must recognize the feature tag and relate it
       to the capabilities that it does have.

       Further, an eifax system is not prevented from
       recognizing and offering additional feature tags.  The
       list below is intended to provide a minimum vocabulary
       which all eifax systems can use in a consistent fashion.

3.1 Image Size

  Feature tag name    Legal values
  ----------------    ------------
  pix-x               <Integer> (>0)
  pix-y               <Integer> (>0)

  Reference: "Media Features for Display, Print, and Fax" [3].


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  [[[The use of pixels as a measure of fax image size is currently
  under discussion: should we use pixels or some physical unit of
  measure?]]]

3.2 Resolution

  Feature tag name    Legal values
  ----------------    ------------
  dpi                 <Integer> (>0)
  dpi-xyratio         <Rational> (>0)

  Reference: "Media Features for Display, Print, and Fax" [3], and
  this document appendix A.

  [[[The use of resolution and x/y resolution ratio values versus
  using separate x- and y- resolutions is currently under
  discussion]]]

3.3 Media type

  Feature tag name    Legal values
  ----------------    ------------
  ua-media            screen
                      screen-paged
                      stationery
                      transparency
                      envelope
                      envelope-plain
                      continuous

  Reference: "Media Features for Display, Print, and Fax" [3].

  [[[The relevance of media type to Internet fax is currently under
  discussion.  I think it is not relevant.]]]

3.4 Paper Size

  Feature tag name    Legal values
  ----------------    ------------
  paper-size          A4
                      A3
                      B4
                      letter
                      legal

  Reference: "Media Features for Display, Print, and Fax" [3].

  [[[There may be some conflict or interaction between this and
  'image size' above.]]]




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3.5 Color and greyscale

  Feature tag name    Legal values
  ----------------    ------------
  grey                <Integer>
                      (Typically 2,16,256,65536,16777216)
  color               <Integer>
                      (Typically 16,256,65536,16777216)

  Reference: "Media Features for Display, Print, and Fax" [3].

       NOTE: a bi-level (i.e. black-and-white only) fax image or
       capability is indicated by the feature value 'grey=2'.
       This is indicates the rendering capabilities of a
       recipient or requirements of a document, and does not of
       itself indicate a coding scheme.

3.6 Coding

  Feature tag name    Legal values
  ----------------    ------------
  image-coding        MH
                      MR
                      MMR
                      JBIG
                      JBIG-LO
                      JBIG-T43
                      JPEG
  image-interleave    Strip
                      Plane
  color-subsampling   <Boolean>
  MRC-level           <Integer> [0-7]
  MRC-strip           Fullpage
                      Line256

  Reference: this document, appendix A.

3.7 Color model

  Feature tag name    Legal values
  ----------------    ------------
  custom-illuminant   <Boolean>
  custom-gamut        <Boolean>

  Reference: this document, appendix A.








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3.8 Preferred units

  Feature tag name    Legal values
  ----------------    ------------
  preferred-unit      metric
                      inch

  Reference: this document, appendix A.

4. Examples

  <<<to be provided>>>

  <<<Suggested example subjects follow>>

4.1 Simple fax machine

4.2 Grey-scale fax machine

4.3 Full-colour fax machine

4.4 PC-based e-mail recipient

5. Security considerations

  <<<to be provided>>>

6. Full copyright statement

  Copyright (C) The Internet Society 1998.  All Rights Reserved.

  This document and translations of it may be copied and furnished to
  others, and derivative works that comment on or otherwise explain
  it or assist in its implementation may be prepared, copied,
  published and distributed, in whole or in part, without restriction
  of any kind, provided that the above copyright notice and this
  paragraph are included on all such copies and derivative works.
  However, this document itself may not be modified in any way, such
  as by removing the copyright notice or references to the Internet
  Society or other Internet organizations, except as needed for the
  purpose of developing Internet standards in which case the
  procedures for copyrights defined in the Internet Standards process
  must be followed, or as required to translate it into languages
  other than English.

  The limited permissions granted above are perpetual and will not be
  revoked by the Internet Society or its successors or assigns.






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  This document and the information contained herein is provided on
  an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET
  ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
  THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
  WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

7. Acknowledgements

  <<<To be provided>>>

8. References

[1]  "Media Feature Tag Registration Procedure"
     Koen Holtman, TUE
     Andrew Mutz, Hewlett-Packard
     Ted Hardie, NASA
     Internet draft: <draft-ietf-conneg-feature-reg-03.txt>
     Work in progress, July 1998.

[2]  "A syntax for describing media feature sets"
     Graham Klyne, 5GM/Content Technologies
     Internet draft: <draft-ietf-conneg-feature-syntax-00.txt>"
     Work in progress, September 1998.

[3]  "Media Features for Display, Print, and Fax"
     Larry Masinter, Xerox PARC
     Koen Holtman, TUE
     Andrew Mutz, Hewlett-Packard
     Dan Wing, Cisco Systems
     Internet draft: <draft-ietf-conneg-media-features-02.txt>
     Work in progress, September 1998.

[4]  "Internet fax feature mapping from Group 3 fax"
     Lloyd McIntyre, Xerox Corporation
     Graham Klyne, 5GM/Content Technologies
     Internet draft: <draft-ietf-fax-feature-T30-mapping-00.txt>
     Work in progress, August 1998.

[5]  "Extended Facsimile Using Internet Mail
     Larry Masinter, Xerox Corporation
     Dan Wing, Cisco Systems
     Internet draft: <draft-ietf-fax-eifax-04.txt>
     Work in progress, September 1998.

[6]  "Procedures for document facsimile transmission in the general
     switched telephone network"
     ITU-T Recommendation T.30
     International Telecommunications Union
     July 1996



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9. Authors' addresses

  Lloyd McIntyre
  Xerox Corporation
  Mailstop PAHV-305
  3400 Hillview Ave.
  Palo Alto, CA 94304 USA
  Telephone: +1-650-813-6762
  Facsimile: +1-650-845-2340
  E-mail: Lloyd.McIntyre@pahv.xerox.com

  Graham Klyne
  5th Generation Messaging Ltd.    Content Technologies Ltd.
  5 Watlington Street              Forum 1, Station Road
  Nettlebed                        Theale
  Henley-on-Thames, RG9 5AB        Reading, RG7 4RA
  United Kingdom                   United Kingdom.
  Telephone: +44 1491 641 641      +44 118 930 1300
  Facsimile: +44 1491 641 611      +44 118 930 1301
  E-mail: GK@ACM.ORG

Appendix A: Feature registrations

  [[[This appendix contains registrations of media features, that are
  specific to fax and for which no applicable registration already
  exists.]]]



























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