rfc2880.txt

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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.














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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







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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])






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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]) )





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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







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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)



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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)