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rfc:rfc2880

Network Working Group L. McIntyre Request for Comments: 2880 Xerox Corporation Category: Informational G. Klyne

                                                  Content Technologies
                                                           August 2000
                 Internet Fax T.30 Feature Mapping

Status of this Memo

 This memo provides information for the Internet community.  It does
 not specify an Internet standard of any kind.  Distribution of this
 memo is unlimited.

Copyright Notice

 Copyright (C) The Internet Society (2000).  All Rights Reserved.

Abstract

 This document describes how to map Group 3 fax capability
 identification bits, described in ITU T.30 [6], into the Internet fax
 feature schema described in "Content feature schema for Internet fax"
 [4].
 This is a companion to the fax feature schema document [4], which
 itself defines a profile of the media feature registration mechanisms
 [1,2,3], for use in performing capability identification between
 extended Internet fax systems [5].

Table of Contents

 1. Introduction .............................................3
    1.1 Organization of this document ........................3
    1.2 Terminology and document conventions .................3
    1.3 Discussion of this document ..........................4
 2. Combining feature tags ...................................4
    2.1 Relationship to Group 3 fax ..........................5
    2.2 Feature set descriptions .............................5
    2.3 Examples .............................................5
      2.3.1 Data resource example ............................6
      2.3.2 Recipient capabilities example ...................6
 3. Survey of media-related T.30 capability bits .............6
    3.1 DIS/DTC bit 15 (resolution) ..........................6
    3.2 DIS/DTC bit 16 (MR coding) ...........................7
    3.3 DIS/DTC bits 17,18 (width) ...........................7
    3.4 DIS/DTC bits 19,20 (length) ..........................7

McIntyre & Klyne Informational [Page 1] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

    3.5 DIS/DTC bit 31 (MMR coding) ..........................7
    3.6 DIS/DTC bit 36 (JBIG multi-level coding) .............8
    3.7 DIS/DTC bit 37 (plane interleave) ....................8
    3.8 DIS/DTC bits 41,42,43 (resolution) ...................8
    3.9 DIS/DTC bits 44,45 (preferred units) .................9
    3.10 DIS/DTC bit 68 (JPEG) ...............................9
    3.11 DIS/DTC bit 69 (colour) .............................9
    3.12 DIS/DTC bit 71 (bits/sample) .......................10
    3.13 DIS/DTC bit 73 (no subsampling) ....................10
    3.14 DIS/DTC bit 74 (custom illuminant) .................10
    3.15 DIS/DTC bit 75 (custom gamut) ......................10
    3.16 DIS/DTC bits 76,77 (paper size) ....................11
    3.17 DIS/DTC bit 78 (JBIG bi-level coding) ..............11
    3.18 DIS/DTC bit 79 (JBIG stripe size) ..................11
    3.19 DIS/DTC bit 92,93,94 (MRC maximum functional mode) .11
    3.20 DIS/DTC bit 95 (MRC stripe size) ...................12
    3.21 DIS/DTC bit 97 (resolution) ........................12
    3.22 DIS/DTC bit 98 (resolution) ........................12
 4. Summary of T.30 capability dependencies .................12
    4.1 Image coding ........................................13
      4.1.1 Bi-level coding .................................13
      4.1.2 Multi-level coding ..............................14
      4.1.3 MRC format ......................................14
    4.2 Resolution and units ................................15
    4.3 Colour capabilities .................................17
    4.4 Document size .......................................18
 5. Mapping T.30 capabilities to fax feature schema .........18
    5.1 Image coding ........................................20
      5.1.1 Bi-level coding .................................20
      5.1.2 Multi-level coding ..............................21
      5.1.3 MRC format ......................................23
    5.2 Resolution and units ................................23
    5.3 Colour capabilities .................................24
    5.4 Document size .......................................26
 6. Examples ................................................26
    6.1 Common black-and-white fax machine ..................27
      6.1.1 Corresponding Internet fax capabilities .........29
    6.2 Full-featured color fax machine .....................30
 7. Security Considerations .................................34
 8. Acknowledgements ........................................34
 9. References ..............................................34
 10. Authors' Addresses .....................................36
 Full Copyright Statement ...................................37

McIntyre & Klyne Informational [Page 2] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

1. Introduction

 This document describes how to map Group 3 fax capability
 identification bits, described in ITU T.30 [6], into the Internet fax
 feature schema described in "Content feature schema for Internet fax"
 [4].
 This is a companion to the fax feature schema document [4], which
 itself defines a profile of the media feature registration mechanisms
 [1,2,3], for use in performing capability identification between
 extended Internet fax systems [5].

1.1 Organization of this document

 Section 2 introduces the mechanisms that combine feature tag
 constraints to describe complex recipient capabilities.
 Section 3 surveys Group 3 fax (T.30) capability bits that relate to
 media handling capabilities.
 Section 4 describes the dependencies between Group 3 fax (T.30)
 capability bits.  These are presented in a decision table format [16]
 with descriptive text in place of the action bodies.
 Section 5 describes a formal mechanism for converting Group 3 fax
 (T.30) capability masks to fax feature schema statements.  The
 conversion process is driven by the decision tables introduced
 previously, using fax feature schema statements and combining rules
 in the action bodies.
 Section 6 presents an example of a Group 3 fax (T.30) capability
 mask, and uses the formal mechanism described previously to convert
 that into a corresponding fax feature schema statement.

1.2 Terminology and document conventions

 eifax system
           is used to describe any software, device or combination
           of these that conforms to the specification "Extended
           Facsimile Using Internet Mail" [5].
 Feature   is used as defined in [15].  (See also section 2 of this
           memo.)
 Feature tag
           is used as defined in [15].  (See also section 2.)

McIntyre & Klyne Informational [Page 3] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

 Feature collection
           is used as defined in [2].  (See also section 2.)
 Feature set
           is used as defined in [2].  (See also section 2.)

1.3 Discussion of this document

 Discussion of this document should take place on the Internet fax
 mailing list hosted by the Internet Mail Consortium (IMC).  Please
 send comments regarding this document to:
     ietf-fax@imc.org
 To subscribe to this list, send a message with the body 'subscribe'
 to "ietf-fax-request@imc.org".
 To see what has gone on before you subscribed, please see the mailing
 list archive at:
     http://www.imc.org/ietf-fax/

2. Combining feature tags

 A fax document can be described by media features.  Any single media
 feature value can be thought of as just one component of a feature
 collection that describes some instance of a document (e.g.  a
 printed fax, a displayed image, etc.).  Such a feature collection
 consists of a number of media feature tags (each per [1]) and
 associated feature values.
 A feature set contains a number of feature collections.  Thus, a
 feature set can describe a number of different fax document
 instances.  These can correspond to different treatments of a single
 document (e.g. different resolutions used for printing a given fax),
 a number of different documents subjected to a common treatment (e.g.
 the range of different images that can be rendered on a given
 display), or some combination of these (see examples below).
 Thus, a description of a feature set can describe the rendering
 requirements of a fax document or the capabilities of a receiving
 eifax system.

McIntyre & Klyne Informational [Page 4] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

2.1 Relationship to Group 3 fax

 A "feature tag" can be compared with a single bit in a T.30 DCS
 frame, describing a specific attribute of a specific fax document.
 A "feature collection" corresponds to a complete T.30 DCS frame,
 describing a range of attributes of a specific fax document.
 A "feature set" corresponds to a DIS or DTC frame, describing the
 range of document attributes that can be accepted by a given fax
 machine.
 Within T.30 DIS/DTC frames, dependencies between the various
 capabilities are implicit in the definitions of the capabilities.
 E.g. multi-level coding (DIS/DTC bit 68) requires support for
 200*200dpi resolution (DIS/DTC bit 15).  In the feature set
 description framework used by eifax systems [1,2,3,4] such
 dependencies between different features are expressed explicitly.
 Later sections of this memo describe how the implicit dependencies of
 T.30 are expressed using the media feature set notation.

2.2 Feature set descriptions

 The general approach to describing feature sets, described more fully
 in [2], is to use functions ("predicates") that, when applied to a
 feature collection value, yield a Boolean value that is TRUE if the
 feature collection describes an acceptable fax document instance,
 otherwise FALSE.
                    P(F)
      P(F) = TRUE <- : -> P(F) = FALSE
                     :
          +----------:----------+  This box represents some
          |          :          |  universe of fax documents (F)
          | Included : Excluded |  from which some acceptable subset
          |          :          |  is selected by the predicate P.
          +----------:----------+
                     :

2.3 Examples

 In the examples below the following notation is used:
    (x ? y)             tests feature tag 'x' for some relationship
                        with value 'y'.
    (| p1 p2 ... pn )   represents the logical-OR of predicates 'p1',
                        'p2' up to 'pn'.

McIntyre & Klyne Informational [Page 5] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

    (& p1 p2 ... pn )   represents the logical-AND of predicates
                        'p1', 'p2' up to 'pn'.

2.3.1 Data resource example

 The following expression uses the syntax of [2] to describe a data
 resource that can be displayed either:
 (a)  as a 750x500 pixel image using 15 colours, or
 (b)  at 150dpi on an A4 page.
    (| (& (pix-x=750) (pix-y=500) (color=15) )
       (& (dpi>=150) (papersize=A4) ) )

2.3.2 Recipient capabilities example

 The following expression describes a receiving system that has:
 (a)  a screen capable of displaying 640*480 pixels and 16 million
      colours (24 bits per pixel), 800*600 pixels and 64 thousand
      colours (16 bits per pixel) or 1024*768 pixels and 256 colours
      (8 bits per pixel), or
 (b)  a printer capable of rendering 300dpi on A4 paper.
    (| (& (| (& (pix-x<=640)  (pix-y<=480) (color<=16777216) )
             (& (pix-x<=800)  (pix-y<=600) (color<=65535) )
             (& (pix-x<=1024) (pix-y<=768) (color<=256) ) )
          (media=screen) )
       (& (dpi=300)
          (media=stationery) (papersize=A4) ) )

3. Survey of media-related T.30 capability bits

 The following sections refer to T.30 DIS/DTC bits identified and
 described in Table 2/T.30 and accompanying notes [6].  Bit numbers
 that are not referenced below are considered to be not related to
 media features, hence not relevant to the Internet fax feature
 schema.
       NOTE: some of the DIS/DTC bits identified below are
       documented in revisions of the T.30 specification that
       may be not yet publicly available from the ITU.

3.1 DIS/DTC bit 15 (resolution)

 All Group 3 fax systems are required to support a basic resolution of
 200*100dpi (dots per inch) or 8*3.85dpmm (dots per millimetre).
 Setting this bit indicates additional support for 200*200dpi or
 8*7.7dpmm.

McIntyre & Klyne Informational [Page 6] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

 For multi-level images, 200*200dpi is the basic resolution, and this
 bit must be set.  The other basic resolution options apply to bi-
 level images only.
 See also: bits 44,45.

3.2 DIS/DTC bit 16 (MR coding)

 All Group 3 fax systems are required to support Modified Huffman (MH)
 1-dimensional coding for bi-level images.  (A bi-level image is one
 with just two pixel states such as black and white, as opposed to a
 grey-scale or colour image.)
 Setting this bit indicates additional support for Modified Read (MR)
 2-dimensional coding for bi-level images.
 Both MH and MR coding are described in ITU T.4 [7].
 See also: bits 31,78,79.

3.3 DIS/DTC bits 17,18 (width)

 All Group 3 fax systems are required to support 215mm paper width.
 These bits can be set to indicate additional support for 255mm and
 303mm paper widths.
 See also: bits 76,77.

3.4 DIS/DTC bits 19,20 (length)

 All Group 3 fax systems are required to support 297mm paper length.
 These bits can be set to indicate additional support for 364mm and
 unlimited paper lengths.
 See also: bits 76,77.

3.5 DIS/DTC bit 31 (MMR coding)

 Setting this bit indicates support for Modified Modified Read (MMR)
 2-dimensional coding for bi-level images, in addition to the required
 support for MH coding.
 MMR coding is described in ITU T.6 [8].
 See also: bits 16,78,79.

McIntyre & Klyne Informational [Page 7] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

3.6 DIS/DTC bit 36 (JBIG multi-level coding)

 If multi-level images are to be handled, support for JPEG coding is
 required (i.e. bit 68 must be set).  Setting bit 36 indicates
 additional support for JBIG lossless coding of multi-level images.
 JBIG coding for multi-level images is described in ITU T.43 [10] and
 T.4 Annex G [7].
 See also: bits 68,69.

3.7 DIS/DTC bit 37 (plane interleave)

 Setting this bit indicates support for plane interleave for JBIG-
 coded multi-level images in addition to stripe interleave, which is
 standard for JBIG multi-level images.
 JBIG coding for multi-level images is described in ITU T.43 [10] and
 T.4 Annex G [7].
 See also: bit 36.

3.8 DIS/DTC bits 41,42,43 (resolution)

 Setting these bits indicates support for resolutions in addition to
 200*100dpi and 200*200dpi, or 8*3.85dpmm and 8*7.7dpmm.  (Or in
 addition to the basic 200*200dpi resolution when using a multi-level
 image mode.)
 Bit 41 indicates support for 8*15.4dpmm bi-level images
 (independently of the settings of bits 44 and 45).
 Bit 42 indicates support for 300*300dpi bi-level images
 (independently of the settings of bits 44 and 45).  Also applies to
 multi-level images or MRC mask if bit 97 is set.
 Bit 43 indicates support for 400*400dpi and/or 16*15.4dpmm bi-level
 images, depending upon the settings of bits 44 and 45.  Also applies
 to multi-level images or MRC mask if bit 97 is set.
 See also: bits 15,44,45,97.

McIntyre & Klyne Informational [Page 8] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

3.9 DIS/DTC bits 44,45 (preferred units)

 These bits are used to indicate the preferred resolution units for
 received images.  Because the exact resolution and x/y pixel density
 measures in dpi or dpmm are slightly different, some image size and
 aspect ratio distortion may occur if the sender and receiver use
 different units.
 Even when sender and recipient have different preferred units, image
 transfer must be accomplished.  For most fax uses, the dpi and dpmm
 measurements are sufficiently close to each other that the difference
 is not noticed.
 The preferred units setting affects the detailed interpretation of
 the following resolutions:
              dpi       dpmm      (dpi equivalent)
              ---       ----
    Base      200*100   8*3.85    204*98
    Bit 15    200*200   8*7.7     204*196
    Bit 43    400*400   16*15.4   408*391
 But terminals are required to accept the inch- and metric-based
 measures given above as equivalent, distorting the image if necessary
 to accommodate the differences.
 See also: bits 15, 43

3.10 DIS/DTC bit 68 (JPEG)

 This bit indicates support for JPEG coding of multi-level images.
 JPEG coding for multi-level images is described in ITU T.81 [12] and
 T.4 Annex E [7].
 See also: bits 15,69,73

3.11 DIS/DTC bit 69 (colour)

 This bit indicates support for colour images, in addition to just
 grey-scale.
 Both grey-scale and colour require multi-level coding.  The
 difference is that grey is single component while colour is multi-
 component.
 See also: bits 36,68,73.

McIntyre & Klyne Informational [Page 9] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

3.12 DIS/DTC bit 71 (bits/sample)

 Standard support for multi-level images uses 8 bits per sample.
 Setting this bit indicates additional support for 12 bits per sample.
 For a grey-scale multi-level image, there is just one sample per
 pixel, giving 256 or 4096 possible pixel values.  For a full colour
 multi-level image there are three samples per pixel, giving 256^3
 (16777216) or 4096^3 (6871946736) possible values.
 When related to a mapped colour image, bit 71 also affects the
 maximum number of entries in the mapping table:  when it is reset, up
 to 4096 different pixel values can be used;  when set, up to 65536
 different values can be used.
 See also: bit 68.

3.13 DIS/DTC bit 73 (no subsampling)

 Standard support for JPEG-coded multi-level images uses 4:1:1
 chrominance subsampling.  That is, for each 4 luminance samples in
 the image data there is a single chrominance sample.
 Setting this bit indicates that JPEG-coded colour images without
 subsampling can also be supported.  This is not applicable to JBIG
 coding (bit 36).
 See also: bits 68,69.

3.14 DIS/DTC bit 74 (custom illuminant)

 Standard support for multi-level images requires use of D50
 illuminant.  Setting this bit indicates that a custom illuminant also
 can be supported for multi-level images (both grey-scale and colour).
 Details of the custom illuminant are contained in the image data.
 Use of a custom illuminant with multi-level images is described in
 ITU T.4 Annex E [7].
 See also: bits 36,68.

3.15 DIS/DTC bit 75 (custom gamut)

 Standard support for a default colour gamut is required for multi-
 level images.  Setting this bit indicates that a custom gamut also
 can be supported for multi-level images (both grey-scale and colour).
 Details of the custom gamut are contained in the image data.

McIntyre & Klyne Informational [Page 10] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

 The default gamut (L*=[0,100], a*=[-85, 85], b* = [-75, 125]), and
 use of a custom gamut with multi-level images is described in ITU
 T.42 [9] and T.4 Annex E [7].
 See also: bits 36,68.

3.16 DIS/DTC bits 76,77 (paper size)

 All Group 3 faxes are required to support A4 paper size.  These bits
 can be set to indicate additional support for North American letter
 and legal paper sizes.
 See also: bits 17,18,19,20.

3.17 DIS/DTC bit 78 (JBIG bi-level coding)

 Setting bit 78 indicates support for JBIG coding of bi-level images
 (using T.85 encoding rules), in addition to the required support for
 MH coding.
 JBIG coding of bi-level images is described in ITU T.85 [14].
 See also: bits 16,31,79.

3.18 DIS/DTC bit 79 (JBIG stripe size)

 Setting bit 79 (along with bit 78) indicates support for the 'LO'
 option with JBIG coded bi-level images.  Basic bi-level JBIG coding
 uses 128 lines per stripe;  the 'LO' option allows other stripe sizes
 to be used.
 The stripe size is used for all stripes except the last, which may
 have fewer lines than the indicated value.
 JBIG coding of bi-level images is described in ITU T.85 [14].
 See also: bits 16,31,78.

3.19 DIS/DTC bit 92,93,94 (MRC maximum functional mode)

 If these bits are all zero, then Mixed Raster Content (MRC) coding is
 not supported.  Otherwise, they represent a number in the range 1-7
 that indicates an MRC maximum functional mode.
 MRC coding of images is described in ITU T.44 [11] and T.4 Annex H
 [17].
 See also: bits 68,95.

McIntyre & Klyne Informational [Page 11] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

3.20 DIS/DTC bit 95 (MRC stripe size)

 Standard support for MRC uses a maximum stripe size of 256 lines.
 When this bit is set, the maximum stripe size is a full page.
 This bit is meaningful only if bits 92-94 indicate an MRC coding
 capability.  MRC coding of images is described in ITU T.44 [11] and
 T.4 Annex H [17].
 See also: bits 92,93,94.

3.21 DIS/DTC bit 97 (resolution)

 Setting this bit indicates that the additional resolutions indicated
 by bits 42 and 43 may be used for multi-level images and any MRC mask
 layer.
 When this bit is set, bit 42 implies 300dpi and bit 43 implies 400dpi
 for multi-level or MRC mask layer images (irrespective of the
 preferred units indicated by bits 44 and 45).
 See also: bits 42,43,68.

3.22 DIS/DTC bit 98 (resolution)

 Setting this bit indicates that the additional resolution 100*100dpi
 may be used for multi-level images.
      NOTE: 100dpi is not used for bi-level images, including
      the MRC mask layer.
 See also: bit 36,68,92-94.

4. Summary of T.30 capability dependencies

 This section contains a number of decision tables that indicate the
 allowable combinations of T.30 DIS/DTC mask bits.
 Within the decision table bodies, the following symbols are use to
 indicate values of T.30 DIS/DTC bits:
    0  = bit set to '0'
    1  = bit set to '1'
    x  = don't care bit value: may be '0' or '1'
    *0 = bit must be '0' ('1' is invalid in given combination)
    *1 = bit must be '1' ('0' is invalid in given combination)
    #  = bits in row combined to form a numeric value

McIntyre & Klyne Informational [Page 12] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

4.1 Image coding

 MH coding is required as a minimum for Group 3 fax operation.

4.1.1 Bi-level coding

←—— T.30 bits ———> 15|16|31|36|37|68|69|73|78|79||Description –+–+–+–+–+–+–+–+–+–++————————————— x| 0| 0| | | | | | 0| 0||Compression = [MH] x| 1| 0| | | | | | 0| 0||Compression = [MH,MR] x| 0| 1| | | | | | 0| 0||Compression = [MH,MMR] x| 1| 1| | | | | | 0| 0||Compression = [MH,MR,MMR] x| 0| 0| | | | | | 1| 0||Compression = [MH,T.85] x| 1| 0| | | | | | 1| 0||Compression = [MH,MR,T.85] x| 0| 1| | | | | | 1| 0||Compression = [MH,MMR,T.85] x| 1| 1| | | | | | 1| 0||Compression = [MH,MR,MMR,T.85] x| 0| 0| | | | | |*1| 1||Compression = [MH,T.85,T.85LO] x| 1| 0| | | | | |*1| 1||Compression = [MH,MR,T.85,T.85LO] x| 0| 1| | | | | |*1| 1||Compression = [MH,MMR,T.85,T.85LO] x| 1| 1| | | | | |*1| 1||Compression = [MH,MR,MMR,T.85,T.85LO]

|  |  |  |  |  |  |  |  |  ||MH     = 1-D per T.4
|  |  |  |  |  |  |  |  |  ||MR     = 2-D per T.4
|  |  |  |  |  |  |  |  |  ||MMR    = 2-D per T.6
|  |  |  |  |  |  |  |  |  ||T.85   = Basic JBIG per T.85
|  |  |  |  |  |  |  |  |  ||T.85LO = Optional LO with T.85/JBIG
|  |  |  |  |  |  |  |  |  ||(Basic JBIG is 128 lines/stripe;  LO
|  |  |  |  |  |  |  |  |  || allows other stripe sizes to be used)

–+–+–+–+–+–+–+–+–+–++—————————————

McIntyre & Klyne Informational [Page 13] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

4.1.2 Multi-level coding

 Note: When 37, 69, 73, 79 and 95 are set to "1", the feature
 represented by "0" is also available.  Example: If plane interleave
 is available then stripe interleave is also available.

←—— T.30 bits ———> 15|16|31|36|37|68|69|73|78|79||Description –+–+–+–+–+–+–+–+–+–++————————————— x| | |*0| x| 0| x| x| | ||No grey or colour (no T.43 or JPEG) *1| | | 0| x| 1| 0| x| | ||JPEG, grey scale only *1| | | 0| x| 1| 1| 0| | ||JPEG, full colour, subsampling *1| | | 0| x| 1| 1| 1| | ||JPEG, full colour, no subsampling *1| | | 1| 0|*1| 0| x| | ||T.43, JPEG, grey only, stripe i/l *1| | | 1| 1|*1| 0| x| | ||T.43, JPEG, grey only, plane i/l *1| | | 1| 0|*1| 1| 0| | ||T.43, JPEG, colour, stripe i/l, s/s *1| | | 1| 0|*1| 1| 1| | ||T.43, JPEG, colour, stripe i/l, no s/s *1| | | 1| 1|*1| 1| 0| | ||T.43, JPEG, colour, plane i/l, s/s *1| | | 1| 1|*1| 1| 1| | ||T.43, JPEG, colour, plane i/l, no s/s

|  |  |  |  |  |  |  |  |  ||'s/s'    is 4:1:1 L*:a*:b* subsampling
|  |  |  |  |  |  |  |  |  ||'No s/s' is 1:1:1 L*:a*:b* subsampling
|  |  |  |  |  |  |  |  |  ||'stripe i/l' is stripe interleave
|  |  |  |  |  |  |  |  |  ||'plane i/l'  is full-plane interleave

–+–+–+–+–+–+–+–+–+–++—————————————

4.1.3 MRC format

 Multi-level coders, as indicated above, are used for foreground and
 background images within an MRC-format document.  Bi-level codes
 are used for the mask layer.

←— T.30 bits ——> 15|92|93|94|95| | | ||Description –+–+–+–+–+–+–+–++————————————— x| 0| 0| 0| x| | | ||MRC not accepted *1| #| #| #| 0| | | ||MRC level, max strip 256 lines *1| #| #| #| 1| | | ||MRC level, max strip full page

|  |  |  |  |  |  |  ||### is MRC performance level (1-7, per T.44)

–+–+–+–+–+–+–+–++—————————————

McIntyre & Klyne Informational [Page 14] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

4.2 Resolution and units

 Support for bi-level coding at least one of 200*100dpi or 8*3.85dpmm
 is required in all cases for Group 3 fax conformance.  For multi-
 level coders (colour/grey) and MRC mask layers the base resolution is
 200*200dpi (i.e. bit 15 must be set).
 When multi-level coders (JPEG or T.43) or MRC are used, only inch-
 based square resolutions are available.  However, the base non-square
 resolution (i.e. 200x100dpi or 8x3.85dpmm) must still be available as
 a capability for use with the mandatory bi-level coder (MH).  Hence,
 any references to metric and non-square resolutions in the table
 below apply only to bi-level coders.
 When describing MRC capabilities, the complete set of usable
 resolutions is listed.  However, there are some restrictions on their
 use:  (a) 100dpi resolution can be used only with multi-level images,
 and (b) any multi-level image resolution is required to be an
 integral sub-multiple of the applicable mask resolution.
 In the following table:
    dpi  = dots per inch
    dpmm = dots per millimetre
 Preferred resolutions are indicated here, even though inch- or mm-
 based units must be accepted, according to the T.30 protocol [6].

McIntyre & Klyne Informational [Page 15] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

←—— T.30 bits ——> 15|41|42|43|44|45|68|97|98||Description –+–+–+–+–+–+–+–+–++—————————————– 0| | | 0| x| x| | | ||Resolution = base only

|  |  |  |  |  |  |  |  ||

1| | | 0| 0| 0| | | ||Invalid 1| | | 0| 0| 1| | | ||Resolution = 8*3.85dpmm or 8*7.7dpmm 1| | | 0| 1| 0| | | ||Resolution = 200*100dpi or 200*200dpi 1| | | 0| 1| 1| | | ||Resolution = 8*3.85dpmm or 8*7.7dpmm

|  |  |  |  |  |  |  |  ||        or   200*100dpi or 200*200dpi
|  |  |  |  |  |  |  |  ||

0| | | 1| 0| 0| | | ||Invalid 0| | | 1| 0| 1| | | ||Resolution = 8*3.85dpmm or 16*15.4dpmm 0| | | 1| 1| 0| | | ||Resolution = 200*100dpi or 400*400dpi 0| | | 1| 1| 1| | | ||Resolution = 8*3.85dpmm or 16*15.4dpmm

|  |  |  |  |  |  |  |  ||        or   200*100dpi or 400*400dpi
|  |  |  |  |  |  |  |  ||

1| | | 1| 0| 0| | | ||Invalid 1| | | 1| 0| 1| | | ||Resolution = 8*3.85dpmm or 8*7.7dpmm

|  |  |  |  |  |  |  |  ||        or   16*15.4dpmm

1| | | 1| 1| 0| | | ||Resolution = 200*100dpi or 200*200dpi

|  |  |  |  |  |  |  |  ||        or   400*400dpi

1| | | 1| 1| 1| | | ||Resolution = 8*7.7dpmm or 8*7.7dpmm

|  |  |  |  |  |  |  |  ||        or   16*15.4dpmm
|  |  |  |  |  |  |  |  ||        or   200*100dpi or 200*200dpi
|  |  |  |  |  |  |  |  ||        or   400*400dpi

–+–+–+–+–+–+–+–+–++—————————————–

| 0|  |  |  |  |  |  |  ||Resolutions as above
| 1|  |  |  |  |  |  |  ||Also supports 8*15.4dpmm (bi-level only)
|  |  |  |  |  |  |  |  ||Independent of bits 44,45

–+–+–+–+–+–+–+–+–++—————————————–

|  | 0|  |  |  |  |  |  ||Resolutions as above
|  | 1|  |  |  |  |  |  ||Also supports 300*300dpi
|  |  |  |  |  |  |  |  ||Independent of bits 44,45

–+–+–+–+–+–+–+–+–++—————————————–

|  |  |  |  |  | x| 0|  ||Resolutions as above
|  |  |  |  |  |*1| 1|  ||Also 300*300dpi or 400*400dpi (see below)
|  |  |  |  |  |  |  |  ||(Applies colour, grey-scale or MRC mask)
|  |  |  |  |  |  |  |  ||(Valid only when bit 42 or 43 is set.)
|  |  |  |  |  |  |  |  ||(42 => 300dpi, 43=>400dpi)

–+–+–+–+–+–+–+–+–++—————————————–

|  |  |  |  |  | x|  | 0||Resolutions as above
|  |  |  |  |  |*1|  | 1||Also 100*100dpi
|  |  |  |  |  |  |  |  ||(Applies colour or grey-scale only)
|  |  |  |  |  |  |  |  ||(Independent of bits 44,45)

–+–+–+–+–+–+–+–+–++—————————————–

McIntyre & Klyne Informational [Page 16] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

4.3 Colour capabilities

 Bit 68 (JPEG) is required for any colour/grey scale mode, and bit 36
 indicates additional T.43 capability.

←—— T.30 bits —> 36|68|69|71|74|75| | ||Description –+–+–+–+–+–+–+–++—————————————– 0| 0| x| | | | | ||No grey scale or colour x| 1| 0| | | | | ||Grey scale only 0| 1| 1| | | | | ||Full colour capability (CIE L*a*b*) 1|*1| 1| | | | | ||Full and limited colour capability:

|  |  |  |  |  |  |  || (CIE L*a*b*, palette, RGB 1 bit/colour
|  |  |  |  |  |  |  ||  and CMY(K)1 bit/colour)

–+–+–+–+–+–+–+–++—————————————–

| 0|  | x|  |  |  |  ||
| 1|  | 0|  |  |  |  ||8 bits/pixel and up to 4096 palette entries
| 1|  | 1|  |  |  |  ||8 or 12 bits/pixel, 65536 palette entries

–+–+–+–+–+–+–+–++—————————————–

| 0|  |  | x|  |  |  ||
| 1|  |  | 0|  |  |  ||CIE standard illuminant D50 (per T.42)
| 1|  |  | 1|  |  |  ||Custom illuminants (definition provided)

–+–+–+–+–+–+–+–++—————————————–

| 0|  |  |  | x|  |  ||
| 1|  |  |  | 0|  |  ||Default gamut (per T.42)
| 1|  |  |  | 1|  |  ||Custom gamuts (definition provided)

–+–+–+–+–+–+–+–++—————————————–

McIntyre & Klyne Informational [Page 17] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

4.4 Document size

 A4 width (215mm) is required as a minimum for Group 3 fax
 conformance.  A Group 3 fax machine must always be able to receive
 an A4 image.

←— T.30 bits ——> 17|18|19|20|76|77| | ||Description –+–+–+–+–+–+–+–++—————————————– 0| 0| | | | | | ||Width = 215mm 1| 0| | | | | | ||Width = 215mm or 255mm 0| 1| | | | | | ||Width = 215mm, 255mm or 303mm 1| 1| | | | | | ||Invalid - interpret as (17=0,18=1)

|  |  |  |  |  |  |  ||(measurements described as scan line length)
|  |  |  |  |  |  |  ||(corresp. inch measurements: T.4 sect 2.2)

–+–+–+–+–+–+–+–++—————————————–

|  | 0| 0|  |  |  |  ||Length = 297mm (A4)
|  | 1| 0|  |  |  |  ||Length = 297mm (A4) or 364mm (B4)
|  | 0| 1|  |  |  |  ||Length = unlimited
|  | 1| 1|  |  |  |  ||Invalid

–+–+–+–+–+–+–+–++—————————————–

|  |  |  | 0| 0|  |  ||Papersize = A4
|  |  |  | 1| 0|  |  ||Papersize = A4 or NA-Letter
|  |  |  | 0| 1|  |  ||Papersize = A4 or NA-Legal
|  |  |  | 1| 1|  |  ||Papersize = A4 or NA-Letter or NA-Legal
|  |  |  |  |  |  |  ||(These in addition to paper sizes implied
|  |  |  |  |  |  |  || by bits 17-20 above)

–+–+–+–+–+–+–+–++—————————————–

5. Mapping T.30 capabilities to fax feature schema

 This section follows the structure of the previous section, except
 that the decision tables are restated with feature set expression
 mappings in the action stub.  The feature set expressions use media
 feature tags presented in "Content feature schema for Internet fax"
 [4].
 To construct a feature set expression corresponding to a collection
 of DIS frame bits:
 o  Compare the DIS bits with each decision table in the following
    sections (5.1 to 5.4).  Some decision tables consist of a number
    of sub-tables separated by horizontal lines.
 o  The DIS bits will match exactly one row from each table or sub-
    table:  collect the corresponding feature set expression from the
    action stub (the right hand column of the table).

McIntyre & Klyne Informational [Page 18] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

 o  In the case of the table in section 5.2, which consists of
    several sub-tables, combine the feature set expressions from each
    sub-table with a logical-OR:  (| s1 s2 ... sn ), where 's1', 's2'
    etc. are the feature set expressions selected from each sub-
    table.  In this way, a single feature set expression is obtained
    for the table.
 o  In the case of the tables in sections 5.3 and 5.4, combine the
    sub-table expressions with a logical-AND:  (& s1 s2 ... sn ).
 o  Combine the feature set expressions for each table as follows:
      (& (| T511 T512 ) T513 T52 T53 T54 )
    where:
  1. T511 is the feature set expression obtained from the table in

section 5.1.1

  1. T512 is obtained from the table in section 5.1.2
  1. T513 is obtained from the table in section 5.1.3
  1. T52 is obtained from the table in section 5.2
  1. T53 is obtained from the table in section 5.3
  1. T54 is obtained from the table in section 5.4
 The resulting expression is the feature set expression corresponding
 to the DIS bits given.  Remember that there may be other capabilities
 not expressed by the DIS bits that should be incorporated into the
 final feature expression (e.g. TIFF image file structure).
 To do the reverse transformation, match the feature set to each row
 of each decision table using the matching algorithm in RFC 2533 [2],
 and OR together the DIS bit masks for each row whose feature set
 expression is completely contained by (i.e. is a subset of) that
 given (where the bit value in a table is 'x', use '0').
 A feature set A is completely contained by B if the feature set match
 of A and B (obtained by applying the feature set matching algorithm
 in [2]) is equal to A.

McIntyre & Klyne Informational [Page 19] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

5.1 Image coding

5.1.1 Bi-level coding

←—— T.30 bits ———> 15|16|31|36|37|68|69|73|78|79||Feature set expression –+–+–+–+–+–+–+–+–+–++————————————— x| 0| 0| | | | | | 0| 0||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH]) )

x| 1| 0| | | | | | 0| 0||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH,MR])

x| 0| 1| | | | | | 0| 0||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH,MMR])

x| 1| 1| | | | | | 0| 0||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH,MR,MMR])

x| 0| 0| | | | | | 1| 0||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=JBIG-T85)
|  |  |  |  |  |  |  |  |  ||   (JBIG-stripe-size=128) )

x| 1| 0| | | | | | 1| 0||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH,MR,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=JBIG-T85)
|  |  |  |  |  |  |  |  |  ||   (JBIG-stripe-size=128) )

x| 0| 1| | | | | | 1| 0||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH,MMR,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=JBIG-T85)
|  |  |  |  |  |  |  |  |  ||   (JBIG-stripe-size=128) )

x| 1| 1| | | | | | 1| 0||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH,MR,MMR,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=JBIG-T85)
|  |  |  |  |  |  |  |  |  ||   (JBIG-stripe-size=128) )

x| 0| 0| | | | | |*1| 1||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=JBIG-T85)
|  |  |  |  |  |  |  |  |  ||   (JBIG-stripe-size>=0) )

x| 1| 0| | | | | |*1| 1||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH,MR,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=JBIG-T85)
|  |  |  |  |  |  |  |  |  ||   (JBIG-stripe-size>=0) )

x| 0| 1| | | | | |*1| 1||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH,MMR,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=JBIG-T85)
|  |  |  |  |  |  |  |  |  ||   (JBIG-stripe-size>=0) )

x| 1| 1| | | | | |*1| 1||(& (color=binary)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[MH,MR,MMR,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=JBIG-T85)
|  |  |  |  |  |  |  |  |  ||   (JBIG-stripe-size>=0) )

–+–+–+–+–+–+–+–+–+–++—————————————

McIntyre & Klyne Informational [Page 20] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

5.1.2 Multi-level coding

←—— T.30 bits ———> 15|16|31|36|37|68|69|73|78|79||Feature set expression –+–+–+–+–+–+–+–+–+–++————————————— x| | |*0| x| 0| x| x| | || *1| | | 0| x| 1| 0| x| | ||(& (color=grey)

|  |  |  |  |  |  |  |  |  ||   (image-coding=JPEG)
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=JPEG-T4E) )

*1| | | 0| x| 1| 1| 0| | ||(& (color=[grey,full])

|  |  |  |  |  |  |  |  |  ||   (image-coding=JPEG)
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=JPEG-T4E)
|  |  |  |  |  |  |  |  |  ||   (& (color=full)
|  |  |  |  |  |  |  |  |  ||      (color-subsampling="4:1:1") ) )

*1| | | 0| x| 1| 1| 1| | ||(& (color=[grey,full])

|  |  |  |  |  |  |  |  |  ||   (image-coding=JPEG)
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=JPEG-T4E)
|  |  |  |  |  |  |  |  |  ||   (& (color=full)
|  |  |  |  |  |  |  |  |  ||      (color-subsampling=
|  |  |  |  |  |  |  |  |  ||       ["1:1:1","4:1:1"]) ) )

*1| | | 1| 0|*1| 0| x| | ||(& (color=grey)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[JPEG,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=
|  |  |  |  |  |  |  |  |  ||    [JPEG-T4E,JBIG-T43])
|  |  |  |  |  |  |  |  |  ||   (image-interleave=stripe) )

*1| | | 1| 1|*1| 0| x| | ||(& (color=grey)

|  |  |  |  |  |  |  |  |  ||   (image-coding=[JPEG,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=
|  |  |  |  |  |  |  |  |  ||    [JPEG-T4E,JBIG-T43])
|  |  |  |  |  |  |  |  |  ||   (image-interleave=[stripe,plane]) )

*1| | | 1| 0|*1| 1| 0| | ||(& (color=[limited,mapped,grey,full])

|  |  |  |  |  |  |  |  |  ||   (image-coding=[JPEG,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=
|  |  |  |  |  |  |  |  |  ||    [JPEG-T4E,JBIG-T43])
|  |  |  |  |  |  |  |  |  ||   (& (color=full)
|  |  |  |  |  |  |  |  |  ||      (color-subsampling="4:1:1"]) )
|  |  |  |  |  |  |  |  |  ||   (image-interleave=stripe) )

*1| | | 1| 0|*1| 1| 1| | ||(& (color=[limited,mapped,grey,full])

|  |  |  |  |  |  |  |  |  ||   (image-coding=[JPEG,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=
|  |  |  |  |  |  |  |  |  ||    [JPEG-T4E,JBIG-T43])
|  |  |  |  |  |  |  |  |  ||   (& (color=full)
|  |  |  |  |  |  |  |  |  ||      (color-subsampling=
|  |  |  |  |  |  |  |  |  ||       ["1:1:1","4:1:1"]) )
|  |  |  |  |  |  |  |  |  ||   (image-interleave=stripe) )

McIntyre & Klyne Informational [Page 21] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

*1| | | 1| 1|*1| 1| 0| | ||(& (color=[limited,mapped,grey,full])

|  |  |  |  |  |  |  |  |  ||   (image-coding=[JPEG,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=
|  |  |  |  |  |  |  |  |  ||    [JPEG-T4E,JBIG-T43])
|  |  |  |  |  |  |  |  |  ||   (& (color=full)
|  |  |  |  |  |  |  |  |  ||      (color-subsampling="4:1:1"]) )
|  |  |  |  |  |  |  |  |  ||   (image-interleave=[stripe,plane]) )

*1| | | 1| 1|*1| 1| 1| | ||(& (color=[limited,mapped,grey,full])

|  |  |  |  |  |  |  |  |  ||   (image-coding=[JPEG,JBIG])
|  |  |  |  |  |  |  |  |  ||   (image-coding-constraint=
|  |  |  |  |  |  |  |  |  ||    [JPEG-T4E,JBIG-T43])
|  |  |  |  |  |  |  |  |  ||   (& (color=full)
|  |  |  |  |  |  |  |  |  ||      (image-coding=JPEG)
|  |  |  |  |  |  |  |  |  ||      (color-subsampling=
|  |  |  |  |  |  |  |  |  ||       ["1:1:1","4:1:1"]) )
|  |  |  |  |  |  |  |  |  ||   (image-interleave=[stripe,plane]) )

–+–+–+–+–+–+–+–+–+–++————————————— 15|16|31|36|37|68|69|73|78|79|| –+–+–+–+–+–+–+–+–+–++—————————————

5.1.3 MRC format

←— T.30 bits ——> 15|92|93|94|95| | | ||Feature set expression –+–+–+–+–+–+–+–++————————————— x| 0| 0| 0| x| | | ||(MRC-mode=0) *1| #| #| #| 0| | | ||(& (MRC-mode⇐###)

|  |  |  |  |  |  |  ||   (MRC-max-stripe-size=[0..256]) )

*1| #| #| #| 1| | | ||(& (MRC-mode⇐###)

|  |  |  |  |  |  |  ||   (MRC-max-stripe-size>=0) )

–+–+–+–+–+–+–+–++—————————————

McIntyre & Klyne Informational [Page 22] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

5.2 Resolution and units

←—— T.30 bits ——> 15|41|42|43|44|45|68|97|98||Feature set expression –+–+–+–+–+–+–+–+–++—————————————– 0| | | 0| | | | | ||(& (color=binary)

|  |  |  |  |  |  |  |  ||   (| (& (dpi=200) (dpi-xyratio=200/100) )
|  |  |  |  |  |  |  |  ||      (& (dpi=204)
|  |  |  |  |  |  |  |  ||         (dpi-xyratio=204/98) ) ) )
|  |  |  |  |  |  |  |  ||

1| | | 0| | | | | ||(| (& (color=binary)

|  |  |  |  |  |  |  |  ||      (| (& (dpi=204)
|  |  |  |  |  |  |  |  ||            (dpi-xyratio=204/98) )
|  |  |  |  |  |  |  |  ||         (& (dpi=204)
|  |  |  |  |  |  |  |  ||            (dpi-xyratio=204/196) )
|  |  |  |  |  |  |  |  ||         (& (dpi=200)
|  |  |  |  |  |  |  |  ||            (dpi-xyratio=200/100) ) ) )
|  |  |  |  |  |  |  |  ||   (& (dpi=200) (dpi-xyratio=1) ) )

0| | | 1| | | | | ||(| (& (color=binary)

|  |  |  |  |  |  |  |  ||      (| (& (dpi=204)
|  |  |  |  |  |  |  |  ||            (dpi-xyratio=204/98) )
|  |  |  |  |  |  |  |  ||         (& (dpi=408)
|  |  |  |  |  |  |  |  ||            (dpi-xyratio=408/391) )
|  |  |  |  |  |  |  |  ||         (& (dpi=200)
|  |  |  |  |  |  |  |  ||            (dpi-xyratio=200/100) ) ) )
|  |  |  |  |  |  |  |  ||   (& (dpi=400) (dpi-xyratio=1) ) )

1| | | 1| | | | | ||(| (& (color=binary)

|  |  |  |  |  |  |  |  ||      (| (& (dpi=204)
|  |  |  |  |  |  |  |  ||            (dpi-xyratio=204/98) )
|  |  |  |  |  |  |  |  ||         (& (dpi=204)
|  |  |  |  |  |  |  |  ||            (dpi-xyratio=204/196) )
|  |  |  |  |  |  |  |  ||         (& (dpi=408)
|  |  |  |  |  |  |  |  ||            (dpi-xyratio=408/391) )
|  |  |  |  |  |  |  |  ||         (& (dpi=200)
|  |  |  |  |  |  |  |  ||            (dpi-xyratio=200/100) ) ) )
|  |  |  |  |  |  |  |  ||   (& (dpi=200) (dpi-xyratio=1) )
|  |  |  |  |  |  |  |  ||   (& (dpi=400) (dpi-xyratio=1) ) )

–+–+–+–+–+–+–+–+–++—————————————–

| 0|  |  |  |  |  |  |  ||
| 1|  |  |  |  |  |  |  ||(& (color=binary)
|  |  |  |  |  |  |  |  ||   (dpi=204)
|  |  |  |  |  |  |  |  ||   (dpi-xyratio=204/391) )

–+–+–+–+–+–+–+–+–++—————————————–

|  | 0|  |  |  |  |  |  ||
|  | 1|  |  |  |  |  |  ||(& (dpi=300) (dpi-xyratio=1) )

McIntyre & Klyne Informational [Page 23] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

–+–+–+–+–+–+–+–+–++—————————————–

|  | x| x|  |  | x| 0|  ||
|  | x| 1|  |  |*1| 1|  ||(& (dpi=400) (dpi-xyratio=1) )
|  |*1| 0|  |  |*1| 1|  ||

–+–+–+–+–+–+–+–+–++—————————————–

|  |  |  |  |  | x|  | 0||
|  |  |  |  |  |*1|  | 1||(| (color=binary)
|  |  |  |  |  |  |  |  ||   (& (color=[limited,mapped,grey,full])
|  |  |  |  |  |  |  |  ||      (dpi=100) (dpi-xyratio=1) ) )

–+–+–+–+–+–+–+–+–++—————————————– 15|41|42|43|44|45|68|97|98|| –+–+–+–+–+–+–+–+–++—————————————–

 Note:  all numbers in media feature expressions are integer or
 rational values;  hence the rational number format (n/m) used here.
 Also note:  the preferred unit bits (44,45) are not tested here, as a
 Group 3 fax machine must accept and process either form of units for
 binary images.  All resolutions are expressed in dpi;  here are the
 metric unit equivalents:
 204  ~= (1728/215)*25.4  ~=  8.04dpmm expressed in dpi
 408  ~= (3456/215)*25.4  ~= 16.08dpmm expressed in dpi
  98  ~=  3.85*25.4       ~=  3.85dpmm expressed in dpi
 196  ~=  7.70*25.4       ~=  7.70dpmm expressed in dpi
 391  ~= 15.40*25.4       ~= 15.40dpmm expressed in dpi

5.3 Colour capabilities

←—— T.30 bits —> 36|68|69|71|74|75| | ||Feature set expression –+–+–+–+–+–+–+–++—————————————– 0| 0| x| | | | | || x| 1| 0| | | | | ||(| (color=binary)

|  |  |  |  |  |  |  ||   (& (color=grey)
|  |  |  |  |  |  |  ||      (color-space=CIELAB) ) )

0| 1| 1| | | | | ||(| (color=binary)

|  |  |  |  |  |  |  ||   (& (color=[grey,full])
|  |  |  |  |  |  |  ||      (color-space=CIELAB) ) )

1|*1| 1| | | | | ||(| (color=binary)

|  |  |  |  |  |  |  ||   (& (color=limited)
|  |  |  |  |  |  |  ||      (color-space=[Device-RGB,Device-CMY])
|  |  |  |  |  |  |  ||      (color-levels<=8) )
|  |  |  |  |  |  |  ||   (& (color=limited)
|  |  |  |  |  |  |  ||      (color-space=Device-CMYK)
|  |  |  |  |  |  |  ||      (color-levels<=16) )
|  |  |  |  |  |  |  ||   (& (color=[mapped,grey,full])
|  |  |  |  |  |  |  ||      (color-space=CIELAB) ) )

McIntyre & Klyne Informational [Page 24] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

–+–+–+–+–+–+–+–++—————————————–

| 0|  | x|  |  |  |  ||
| 1|  | 0|  |  |  |  ||(| (color=[binary,limited])
|  |  |  |  |  |  |  ||   (& (color=mapped)
|  |  |  |  |  |  |  ||      (color-levels<=4096) )
|  |  |  |  |  |  |  ||   (& (color=grey)
|  |  |  |  |  |  |  ||      (color-levels<=256) )
|  |  |  |  |  |  |  ||   (& (color=full)
|  |  |  |  |  |  |  ||      (color-levels<=16777216) ) )
| 1|  | 1|  |  |  |  ||(| (color=[binary,limited])
|  |  |  |  |  |  |  ||   (& (color=mapped)
|  |  |  |  |  |  |  ||      (color-levels<=65536) )
|  |  |  |  |  |  |  ||   (& (color=grey)
|  |  |  |  |  |  |  ||      (color-levels<=4096) )
|  |  |  |  |  |  |  ||   (& (color=full)
|  |  |  |  |  |  |  ||      (color-levels<=68719476736) ) )

–+–+–+–+–+–+–+–++—————————————–

| 0|  |  | x|  |  |  ||
| 1|  |  | 0|  |  |  ||(| (color=[binary,limited])
|  |  |  |  |  |  |  ||   (& (color=[mapped,grey,full])
|  |  |  |  |  |  |  ||      (color-illuminant=D50) ) )
| 1|  |  | 1|  |  |  ||   -- Any color illuminant: D50 or custom
|  |  |  |  |  |  |  ||   -- See note below

–+–+–+–+–+–+–+–++—————————————–

| 0|  |  |  | x|  |  ||
| 1|  |  |  | 0|  |  ||(| (color=[binary,limited])
|  |  |  |  |  |  |  ||   (& (color=grey)
|  |  |  |  |  |  |  ||      (CIELAB-L-min>=0)
|  |  |  |  |  |  |  ||      (CIELAB-L-max<=100) )
|  |  |  |  |  |  |  ||   (& (color=[mapped,full])
|  |  |  |  |  |  |  ||      (CIELAB-L-min>=0)
|  |  |  |  |  |  |  ||      (CIELAB-L-max<=100)
|  |  |  |  |  |  |  ||      (CIELAB-a-min>=-85)
|  |  |  |  |  |  |  ||      (CIELAB-a-max<=85)
|  |  |  |  |  |  |  ||      (CIELAB-b-min>=-75)
|  |  |  |  |  |  |  ||      (CIELAB-b-max<=125) ) )
| 1|  |  |  | 1|  |  ||   -- Any color gamut: default or custom

–+–+–+–+–+–+–+–++—————————————– 36|68|69|71|74|75| | ||Feature set expression –+–+–+–+–+–+–+–++—————————————–

    NOTE: the above table assumes the registration of a feature tag
    for color illuminant, values of which are tokens that are the same
    as those described by ITU T.4 [7], Annex E, section E.6.7.

McIntyre & Klyne Informational [Page 25] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

5.4 Document size

 A4 width (215mm) is required as a minimum for Group 3 fax
 conformance.  A Group 3 fax machine must always be able to receive an
 A4 image.

←— T.30 bits ——> 17|18|19|20|76|77| | ||Feature set expression –+–+–+–+–+–+–+–++—————————————– 0| 0| | | | | | ||(Size-x ⇐ 2150/254) 1| 0| | | | | | ||(Size-x ⇐ 2550/254) x| 1| | | | | | ||(Size-x ⇐ 3030/254) –+–+–+–+–+–+–+–++—————————————–

|  | 0| 0|  |  |  |  ||(Size-y <= 2970/254)
|  | 1| 0|  |  |  |  ||(Size-y <= 3640/254)
|  | 0| 1|  |  |  |  ||  -- unlimited
|  | 1| 1|  |  |  |  ||  -- invalid

–+–+–+–+–+–+–+–++—————————————–

|  |  |  | 0| 0|  |  ||(Paper-size=A4)
|  |  |  | 1| 0|  |  ||(Paper-size=[A4,Letter])
|  |  |  | 0| 1|  |  ||(Paper-size=[A4,Legal])
|  |  |  | 1| 1|  |  ||(Paper-size=[A4,Letter,Legal])

–+–+–+–+–+–+–+–++—————————————–

6. Examples

 NOTE:  Although motivated by the requirements of eifax [5], this
 document is concerned with describing capabilities of Group 3 fax
 systems [6].  As such, the algorithms do not of themselves create
 equivalent Internet fax capability statements but, rather, they
 construct capability expressions that might be incorporated into
 those for eifax systems.
 This point is illustrated at the end of the first example below where
 subsection 6.1.1 has been added, which combines T.30 capabilities
 with an appropriate TIFF file format capability to yield an
 expression that might be used to describe an Internet fax system.

McIntyre & Klyne Informational [Page 26] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

6.1 Common black-and-white fax machine

 DIS/DTC
 Bit No.   DIS/DTC bit description                 Value
 -------   -----------------------                 -----
 15        R8 x 7.7 lines/mm and/or                1
           200 x 200 pels/25.4 mm
 16        Two dimensional coding capability       1
 17,18     Recording width capabilities:           0,0
           Scan line length 215 mm + 1%
 19,20     Recording length capability:            01
           unlimited
 31        T.6 (MMR) coding capability             1
 36        T.43 (JBIG) coding capability           0
 37        Plane interleave                        0
 41        Resolution: 8x15.4 dpmm                 0
 42        Resolution: 300x300 dpi                 1
 43        Resolution: 16x15.4 dpmm and/or 400x400 0
           dpi
 68        JPEG coding: not supported              0
 69        Full color mode: not supported          0
 71        12 bits/pel component:  not supported   0
 73        No subsampling (1:1:1):  not supported  0
 74        Custom illuminant:  not supported       0
 75        Custom gamut range:  not supported      0
 76        North American Letter paper size        1
           (8.5"x11") capability
 77        North American Legal paper size         0
           (8.5"x14") capability:  not supported
 78        Single-progression sequential coding    0
           (T.85, bi-level JBIG) basic capability:
           not supported
 79        Single-progression sequential coding    0
           (T.85, bi-level JBIG) optional L0
           capability for other than 128
           lines/stripe:  not supported
 92,93,94  T.44 (Mixed Raster Content) mode:       0,0,0
           not supported
 95        Page length maximum stripe size for MRC 0
           coding:  not supported.
 97        Multi-level resolution 300x300dpi or    0
           400x400dpi:  not supported
 98        Multi-level resolution 100x100dpi:      0
           not supported

McIntyre & Klyne Informational [Page 27] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

 Following the procedure in section 5, matching these DIS bits
 against the decision tables in sections 5.1 to 5.4, we get:
    5.1.1  [Bits 16,31,78,79 = 1,1,0,0]
             (& (color=binary) (image-coding=[MH,MR,MMR]) )
    5.1.2  [Bits 15,36,37,68,69,73 = 1,0,0,0,0,0]
             -- no capabilities
    5.1.3  [Bits 15,92,93,94,95 = 1,0,0,0,0]
             (MRC-mode=0)
    5.2    [Bits 15,43 = 1,0]
             (| (& (color=binary)
                   (| (& (dpi=204)
                         (dpi-xyratio=204/98) )
                      (& (dpi=204)
                         (dpi-xyratio=204/196) )
                      (& (dpi=200)
                         (dpi-xyratio=200/100) ) ) )
                (& (dpi=200) (dpi-xyratio=1) ) )
           [Bit 41 = 0]
             -- no capabilities
           [Bit 42 = 1]
             (& (dpi=300) (dpi-xyratio=1) )
           [Bits 42,43,68,97 = 0,0,0,0]
             -- no capabilities
           [Bits 68,98 = 0,0]
             -- no capabilities
    5.3    [Bits 36,68,69 = 0,0,0]
             -- no capabilities
           [Bits 68,71 = 0,0]
             -- no capabilities
           [Bits 68,74 = 0,0]
             -- no capabilities
           [Bits 68,75 = 0,0]
             -- no capabilities
    5.4    [Bits 17,18 = 0,0]
             (size-x<=2150/254)
           [Bits 19,20 = 0,1]
             -- no capability constraint
           [Bits 76,77 = 1,0]
             (Paper-size=[A4,Letter])

McIntyre & Klyne Informational [Page 28] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

 Combining these as indicated in section 5, we get the following.
 (The initial expression is constructed verbatim per the rules in the
 first part of section 5, even though it contains some redundancy.)
    (& (| (& (color=binary) (image-coding=[MH,MR,MMR]) ) )
       (MRC-mode=0)
       (| (| (& (color=binary)
                (| (& (dpi=204) (dpi-xyratio=204/98)  )
                   (& (dpi=204) (dpi-xyratio=204/196) )
                   (& (dpi=200) (dpi-xyratio=200/100) ) ) )
             (& (dpi=200) (dpi-xyratio=1) ) )
          (& (dpi=300) (dpi-xyratio=1) ) )
       (& (size-x<=2150/254)
          (Paper-size=[A4,Letter]) ) )
 This in turn is simplified as follows.  Note that the expression '(&
 (| (& A B ) ) C ... )' simplifies to just '(& A B C ... )'.
    (& (color=binary)
       (image-coding=[MH,MR,MMR])
       (MRC-mode=0)
       (| (& (dpi=204) (dpi-xyratio=204/98)  )
          (& (dpi=204) (dpi-xyratio=204/196) )
          (& (dpi=200) (dpi-xyratio=200/100) )
          (& (dpi=200) (dpi-xyratio=1) )
          (& (dpi=300) (dpi-xyratio=1) ) )
       (size-x<=2150/254)
       (Paper-size=[A4,Letter]) )

6.1.1 Corresponding Internet fax capabilities

 In the case of an Internet fax device, additional capabilities not
 described by the T.30 DIS frame should be included;  e.g. the
 supported TIFF file structure:
    (& (color=binary)
       (image-file-structure=[TIFF-Limited,TIFF-Minimal])
       (image-coding=[MH,MR,MMR])
       (MRC-mode=0)
       (| (& (dpi=204) (dpi-xyratio=204/98)  )
          (& (dpi=204) (dpi-xyratio=205/196) )
          (& (dpi=200) (dpi-xyratio=200/100) )
          (& (dpi=200) (dpi-xyratio=1) )
          (& (dpi=300) (dpi-xyratio=1) ) )
       (size-x<=2150/254)
       (Paper-size=[A4,Letter]) )

McIntyre & Klyne Informational [Page 29] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

6.2 Full-featured color fax machine

 DIS/DTC
 Bit No.   DIS/DTC bit description                 Value
 -------   -----------------------                 -----
 15        R8 x 7.7 lines/mm and/or                1
           200 x 200 pels/25.4 mm
 16        Two dimensional coding capability       1
 17,18     Recording width capabilities:           0,0
           Scan line length 215 mm + 1%
 19,20     Recording length capability:            01
           unlimited
 31        T.6 (MMR) coding capability             1
 36        T.43 (JBIG) coding capability           0
 37        Plane interleave                        0
 41        Resolution: 8x15.4 dpmm                 1
 42        Resolution: 300x300 dpi                 0
 43        Resolution: 16x15.4 dpmm and/or 400x400 1
           dpi
 68        JPEG coding: supported                  1
 69        Full color mode: supported              1
 71        12 bits/pel component:  not supported   0
 73        No subsampling (1:1:1):  supported      1
 74        Custom illuminant:  not supported       0
 75        Custom gamut range:  not supported      0
 76        North American Letter paper size        1
           (8.5"x11") capability
 77        North American Legal paper size         0
           (8.5"x14") capability:  not supported
 78        Single-progression sequential coding    0
           (T.85, bi-level JBIG) basic capability:
           not supported
 79        Single-progression sequential coding    0
           (T.85, bi-level JBIG) optional L0
           capability for other than 128
           lines/stripe:  not supported
 92,93,94  T.44 (Mixed Raster Content) mode:       0,0,1
           mode 1 supported
 95        Page length maximum stripe size for MRC 1
           coding.
 97        Multi-level resolution 300x300dpi or    1
           400x400dpi:  supported
 98        Multi-level resolution 100x100dpi:      1
           supported

McIntyre & Klyne Informational [Page 30] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

 Matching these DIS bits against the decision tables in sections 5.1
 to 5.4, we get:
    5.1.1  [Bits 16,31,78,79 = 1,1,0,0]
             (& (color=binary) (image-coding=[MH,MR,MMR]) )
    5.1.2  [Bits 15,36,37,68,69,73 = 1,0,0,1,1,1]
             (& (color=[grey,full])
                (image-coding=JPEG)
                (image-coding-constraint=JPEG-T4E)
                (& (color=full)
                   (image-coding=JPEG)
                   (color-subsampling=["1:1:1","4:1:1"]) ) )
    5.1.3  [Bits 15,92,93,94,95 = 1,0,0,1,1]
             (& (MRC-mode<=1) (MRC-max-stripe-size>=0) )
    5.2    [Bits 15,43 = 1,1]
             (| (& (color=binary)
                   (| (& (dpi=204)
                         (dpi-xyratio=204/98) )
                      (& (dpi=204)
                         (dpi-xyratio=204/196) )
                      (& (dpi=408)
                         (dpi-xyratio=408/391) )
                      (& (dpi=200)
                         (dpi-xyratio=200/100) ) ) )
                (& (dpi=200) (dpi-xyratio=1) )
                (& (dpi=400) (dpi-xyratio=1) ) )
           [Bit 41 = 1]
             (& (color=binary)
                (dpi=204) (dpi-xyratio=204/391) )
           [Bit 42 = 0]
             -- no capabilities
           [Bits 42,43,68,97 = 0,1,1,1]
             (& (dpi=400) (dpi-xyratio=1) )
           [Bits 68,98 = 1,1]
             (| (color=binary)
                (& (color=[limited,mapped,grey,full])
                   (dpi=100) (dpi-xyratio=1) ) )
    5.3    [Bits 36,68,69 = 0,1,1]
             (| (color=binary)
                (& (color=[grey,full])
                   (color-space=CIELAB) ) )
           [Bits 68,71 = 1,0]
             (| (color=[binary,limited])
                (& (color=mapped)

McIntyre & Klyne Informational [Page 31] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

                   (color-levels<=4096) )
                (& (color=grey)
                   (color-levels<=256) )
                (& (color=full)
                   (color-levels<=16777216) ) )
           [Bits 68,74 = 1,0]
             (| (color=[binary,limited])
                (& (color=[mapped,grey,full])
                   (color-illuminant=D50) ) )
           [Bits 68,75 = 1,0]
             (| (color=[binary,limited])
                (& (color=grey)
                   (CIELAB-L-min>=0)
                   (CIELAB-L-max<=100) )
                (& (color=[mapped,full])
                   (CIELAB-L-min>=0)
                   (CIELAB-L-max<=100)
                   (CIELAB-a-min>=-85)
                   (CIELAB-a-max<=85)
                   (CIELAB-b-min>=-75)
                   (CIELAB-b-max<=125) ) )
    5.4    [Bits 17,18 = 0,0]
             (size-x<=2150/254)
           [Bits 19,20 = 0,1]
             -- no capability constraint
           [Bits 76,77 = 1,0]
             (Paper-size=[A4,Letter])
 Combining these as indicated in section 5, we get the following:
    (& (| (& (color=binary)
             (image-coding=[MH,MR,MMR]) )
          (& (color=[grey,full])
             (image-coding=JPEG)
             (image-coding-constraint=JPEG-T4E)
             (& (color=full)
                (image-coding=JPEG)
                (color-subsampling=["1:1:1","4:1:1"]) ) )
       (& (MRC-mode<=1) (MRC-max-stripe-size>=0) )
       (| (| (& (color=binary)
                (| (& (dpi=204) (dpi-xyratio=204/98) )
                   (& (dpi=204) (dpi-xyratio=204/196) )
                   (& (dpi=408) (dpi-xyratio=408/391) )
                   (& (dpi=200) (dpi-xyratio=200/100) ) ) )
             (& (dpi=200) (dpi-xyratio=1) )
             (& (dpi=400) (dpi-xyratio=1) ) )
          (& (color=binary)

McIntyre & Klyne Informational [Page 32] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

             (dpi=204) (dpi-xyratio=204/391) )
          (& (dpi=400) (dpi-xyratio=1) )
          (| (color=binary)
             (& (color=[limited,mapped,grey,full])
                (dpi=100) (dpi-xyratio=1) ) ) )
       (& (| (color=binary)
             (& (color=[grey,full]) (color-space=CIELAB) ) )
          (| (color=[binary,limited])
             (& (color=mapped) (color-levels<=4096) )
             (& (color=grey) (color-levels<=256) )
             (& (color=full) (color-levels<=16777216) ) )
          (| (color=[binary,limited])
             (& (color=[mapped,grey,full]) (color-illuminant=D50) ) )
          (| (color=[binary,limited])
             (& (color=grey)
                (CIELAB-L-min>=0)
                (CIELAB-L-max<=100) )
             (& (color=[mapped,full])
                (CIELAB-L-min>=0)
                (CIELAB-L-max<=100)
                (CIELAB-a-min>=-85)
                (CIELAB-a-max<=85)
                (CIELAB-b-min>=-75)
                (CIELAB-b-max<=125) ) ) )
       (& (size-x<=2150/254)
          (Paper-size=[A4,Letter]) ) )
 This in turn simplifies to:
    (| (& (color=binary)
          (image-coding=[MH,MR,MMR])
          (MRC-mode<=1) (MRC-max-stripe-size>=0)
          (| (& (dpi=204) (dpi-xyratio=204/98) )
             (& (dpi=204) (dpi-xyratio=204/196) )
             (& (dpi=204) (dpi-xyratio=204/391) )
             (& (dpi=408) (dpi-xyratio=408/391) )
             (& (dpi=200) (dpi-xyratio=200/100) )
             (& (dpi=200) (dpi-xyratio=1) )
             (& (dpi=400) (dpi-xyratio=1) ) )
          (size-x<=2150/254)
          (Paper-size=[A4,Letter]) )
       (& (color=grey)
          (image-coding=JPEG)
          (image-coding-constraint=JPEG-T4E)
          (MRC-mode<=1) (MRC-max-stripe-size>=0)
          (dpi=[100,200,400]) (dpi-xyratio=1)
          (color-space=CIELAB)
          (color-levels<=256)

McIntyre & Klyne Informational [Page 33] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

          (color-illuminant=D50)
          (CIELAB-L-min>=0)
          (CIELAB-L-max<=100)
          (size-x<=2150/254)
          (Paper-size=[A4,Letter]) )
       (& (color=full)
          (image-coding=JPEG)
          (image-coding-constraint=JPEG-T4E)
          (color-subsampling=["1:1:1","4:1:1"])
          (MRC-mode<=1) (MRC-max-stripe-size>=0)
          (dpi=[100,200,400]) (dpi-xyratio=1)
          (color-space=CIELAB)
          (color-levels<=16777216)
          (color-illuminant=D50)
          (CIELAB-L-min>=0)
          (CIELAB-L-max<=100)
          (CIELAB-a-min>=-85)
          (CIELAB-a-max<=85)
          (CIELAB-b-min>=-75)
          (CIELAB-b-max<=125)
          (size-x<=2150/254)
          (Paper-size=[A4,Letter]) ) )

7. Security Considerations

 Security considerations are discussed in the fax feature schema
 description [4].  This memo is not believed to introduce any
 additional security concerns.

8. Acknowledgements

 The authors gratefully acknowledge the following persons who made
 comments on earlier versions of this memo:  Mr. Hiroshi Tamura and
 and Dr. Robert Buckley.

9. References

 [1]  Holtman, K., Mutz, A. and T. Hardie, "Media Feature Tag
      Registration Procedure", RFC 2506, March 1999.
 [2]  Graham, K., "A syntax for describing media feature sets" RFC
      2533, March 1999.
 [3]  Masinter, L., Holtman, K., Mutz, A. and D. Wing, "Media Features
      for Display, Print, and Fax", RFC 2534, March 1999.
 [4]  Klyne, G. and L. McIntyre, "Content Feature Schema for Internet
      Fax (V2)", RFC 2879, July 2000.

McIntyre & Klyne Informational [Page 34] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

 [5]  Masinter, L. and D. Wing, "Extended Facsimile Using Internet
      Mail", RFC 2532, March 1999.
 [6]  "Procedures for document facsimile transmission in the general
      switched telephone network" ITU-T Recommendation T.30 (1996),
      including Amendment 1 (1997), Amendment 2 (1997), Amendment 3
      (1998) and Amendment 4 (1999) International Telecommunications
      Union
 [7]  "Standardization of Group 3 facsimile terminals for document
      transmission" ITU-T Recommendation T.4 (1996), including
      Amendment 1 (1997), Amendment 2 (1997) and Amendment 3 (1999)
      International Telecommunications Union (Covers basic fax coding
      formats:  MH, MR; Annex E deals with some color image related
      matters, including codes for optional custom illuminants.  Annex
      G deals with some aspects of JBIG encoding of multi-level
      images.)
 [8]  "Facsimile coding schemes and coding control functions for Group
      4 facsimile apparatus" ITU Recommendation T.6 International
      Telecommunications Union (Commonly referred to as the MMR
      standard; covers extended 2-D fax coding format)
 [9]  "Continuous-tone colour representation method for facsimile"
      ITU-T Recommendation T.42 (1996) International
      Telecommunications Union (Covers custom illuminant, gamut)
 [10] "Colour and gray-scale image representation using lossless
      coding scheme for facsimile" ITU-T Recommendation T.43 (1997)
      International Telecommunications Union (Covers JBIG for
      colour/grey images)
 [11] "Mixed Raster Content (MRC)" ITU-T Recommendation T.44 (1999)
      International Telecommunications Union
 [12] "Information technology - Digital compression and coding of
      continuous-tone still image - Requirements and guidelines" ITU-T
      Recommendation T.81 (1992) | ISO/IEC 10918-1:1993 International
      Telecommunications Union (Commonly referred to as JPEG standard)
 [13] "Information technology - Coded representation of picture and
      audio information - Progressive bi-level image compression"
      ITU-T Recommendation T.82 (1993) | ISO/IEC 11544:1993
      International Telecommunications Union (Commonly referred to as
      JBIG1 standard)

McIntyre & Klyne Informational [Page 35] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

 [14] "Application profile for Recommendation T.82 - Progressive bi-
      level image compression (JBIG1 coding scheme for facsimile
      apparatus)" ITU-T Recommendation T.85 (1995), including
      Amendment 1 (1996), Amendment 2 (1997) and Corrigendum 1 (1997)
      International Telecommunications Union (Covers bi-level JBIG)
 [15] Klyne, G., "Protocol-independent Content Negotiation Framework",
      RFC 2703, September 1999.
 [16] "Programs from Decision Tables" E. Humbey Macdonald/American
      Elsevier computer monographs (19), 1973 ISBN 0-444-19569-6/0-
      356-04126-3 (This is an old title, and may not be still in
      print.  It contains a number of references to decision table
      articles published in Communications of the ACM:  August 1967,
      September 1970, January 1966, November 1966, October 1968,
      January 1965, February 1964, June 1970, November 1965, June
      1965, February 1971.)
 [17] "Mixed Raster Content (MRC) mode for G3 facsimile" ITU-T
      Recommendation T.4, Annex H (1999) International
      Telecommunications Union (Covers stripe size)

10. Authors' Addresses

 Lloyd McIntyre
 Xerox Corporation
 Mailstop PAHV-121
 3400 Hillview Ave.
 Palo Alto, CA 94304 USA
 Phone: +1-650-813-6762
 Fax:   +1-650-845-2340
 EMail: Lloyd.McIntyre@pahv.xerox.com
 Graham Klyne
 Content Technologies Ltd.
 1220 Parkview,
 Arlington Business Park
 Theale
 Reading, RG7 4SA
 United Kingdom
 Phone: +44 118 930 1300
 Fax:   +44 118 930 1301
 EMail: GK@ACM.ORG

McIntyre & Klyne Informational [Page 36] RFC 2880 Internet Fax T.30 Feature Mapping August 2000

11. Full Copyright Statement

 Copyright (C) The Internet Society (2000).  All Rights Reserved.
 This document and translations of it may be copied and furnished to
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 or assist in its implementation may be prepared, copied, published
 and distributed, in whole or in part, without restriction of any
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 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
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 followed, or as required to translate it into languages other than
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 The limited permissions granted above are perpetual and will not be
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 This document and the information contained herein is provided on an
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 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
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Acknowledgement

 Funding for the RFC Editor function is currently provided by the
 Internet Society.

McIntyre & Klyne Informational [Page 37]

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