rfc2879.txt

RFC 的详细文档！

4.2 High-end black-and-white Internet fax system

   This would include support for B/W JBIG and be equivalent to what is
   sometimes called "Super G3", except that Internet fax functionality
   would be added.

      (& (image-file-structure=TIFF)
         (MRC-mode=0)
         (color=Binary)
         (| (& (dpi=204) (dpi-xyratio=[204/98,204/196]) )
            (& (dpi=200) (dpi-xyratio=[200/100,1]) )
            (& (dpi=300) (dpi-xyratio=1) ) )
         (| (image-coding=[MH,MR,MMR])
            (& (image-coding=JBIG)
               (image-coding-constraint=JBIG-T85)
               (JBIG-stripe-size=128) ) )
         (size-x<=2150/254)
         (paper-size=[letter,A4,B4]) )
         (ua-media=stationery) )

4.3 Grey-scale Internet fax system

   This is the previous example extended to handle grey scale multi-
   level images.  In keeping with Group 3 fax, this example requires
   equal x- and y- resolutions for a multi-level image.

      (& (image-file-structure=TIFF)
         (MRC-mode=0)
         (| (& (color=Binary)
               (| (image-coding=[MH,MR,MMR])
                  (& (image-coding=JBIG)
                     (image-coding-constraint=JBIG-T85)
                     (JBIG-stripe-size=128) ) )
               (| (& (dpi=204) (dpi-xyratio=[204/98,204/196]) )
                  (& (dpi=200) (dpi-xyratio=[200/100,1]) )
                  (& (dpi=300) (dpi-xyratio=1) ) )
            (& (color=Grey)
               (color-levels<=256)
               (color-space-CIELAB)
               (color-illuminant=D50)
               (CIELAB-L-min>=0)
               (CIELAB-L-max<=100)
               (| (& (image-coding=JPEG)
                     (image-coding-constraint=JPEG-T4E) )
                  (& (image-coding=JBIG)
                     (image-coding-constraint=JBIG-T43)



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RFC 2879      Content Feature Schema for Internet Fax (V2)   August 2000


                     (JBIG-stripe-size=128)
                     (image-interleave=stripe) ) )
               (dpi=[100,200,300]) (dpi-xyratio=1) ) )
         (size-x<=2150/254)
         (paper-size=[letter,A4,B4]) )
         (ua-media=stationery) )

4.4 Full-color Internet fax system (JPEG only)

   This adds 24-bit full-color to the previous example.

      (& (image-file-structure=TIFF)
         (MRC-mode=0)
         (| (& (color=Binary)
               (image-coding=[MH,MR,MMR])
               (| (& (dpi=204) (dpi-xyratio=[204/98,204/196]) )
                  (& (dpi=200) (dpi-xyratio=[200/100,1]) )
                  (& (dpi=300) (dpi-xyratio=1) ) ) )
            (& (color=grey)
               (image-coding=JPEG)
               (image-coding-constraint=JPEG-T4E)
               (color-levels<=256)
               (color-space=CIELAB)
               (color-illuminant=D50)
               (CIELAB-L-min>=0)
               (CIELAB-L-max<=100)
               (dpi=[100,200,300]) (dpi-xyratio=1) )
            (& (color=full)
               (image-coding=JPEG)
               (image-coding-constraint=JPEG-T4E)
               (color-subsampling=["1:1:1","4:1:1"])
               (color-levels<=16777216)
               (color-space=CIELAB)
               (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)
               (dpi=[100,200,300]) (dpi-xyratio=1) ) )
         (size-x<=2150/254)
         (paper-size=[letter,A4,B4]) )
         (ua-media=stationery) )







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RFC 2879      Content Feature Schema for Internet Fax (V2)   August 2000


4.5 Full-color Internet fax system (JPEG and JBIG)

   This adds limited CMY(K), RGB and 16-bit mapped color using JBIG
   coding to the previous example.

      (& (image-file-structure=TIFF)
         (MRC-mode=0)
         (| (& (color=Binary)
               (| (image-coding=[MH,MR,MMR])
                  (& (image-coding=JBIG)
                     (image-coding-constraint=JBIG-T85)
                     (JBIG-stripe-size=128) ) )
               (| (& (dpi=204) (dpi-xyratio=[204/98,204/196]) )
                  (& (dpi=200) (dpi-xyratio=[200/100,1]) )
                  (& (dpi=300) (dpi-xyratio=1) ) ) )
            (& (color=Limited)
               (image-coding=JBIG)
               (image-coding-constraint=JBIG-T43)
               (JBIG-stripe-size=128)
               (image-interleave=stripe)
               (| (& (color-space=[Device-RGB,Device-CMY])
                     (color-levels<=8) )
                  (& (color-space=Device-CMYK)
                     (color-levels<=16) ) )
               (dpi=[100,200,300]) (dpi-xyratio=1) )
            (& (color=Mapped)
               (image-coding=JBIG)
               (image-coding-constraint=JBIG-T43)
               (JBIG-stripe-size=128)
               (image-interleave=stripe)
               (color-levels<=65536)
               (color-space=CIELAB)
               (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)
               (dpi=[100,200,300]) (dpi-xyratio=1) )
            (& (color=grey)
               (| (& (image-coding=JPEG)
                     (image-coding-constraint=JPEG-T4E) )
                  (& (image-coding=JBIG)
                     (image-coding-constraint=JBIG-T43)
                     (JBIG-stripe-size=128)
                     (image-interleave=stripe) ) )
               (color-levels<=256)



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RFC 2879      Content Feature Schema for Internet Fax (V2)   August 2000


               (color-space=CIELAB)
               (color-illuminant=D50)
               (CIELAB-L-min>=0)
               (CIELAB-L-max<=100)
               (dpi=[100,200,300]) (dpi-xyratio=1) )
            (& (color=full)
               (| (& (image-coding=JPEG)
                     (image-coding-constraint=JPEG-T4E)
                     (color-subsampling=["1:1:1","4:1:1"]) )
                  (& (image-coding=JBIG)
                     (image-coding-constraint=JBIG-T43)
                     (JBIG-stripe-size=128)
                     (image-interleave=stripe) ) )
               (color-levels<=16777216)
               (color-space=CIELAB)
               (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)
               (dpi=[100,200,300]) (dpi-xyratio=1) ) )
         (size-x<=2150/254)
         (paper-size=[letter,A4,B4]) )
         (ua-media=stationery) )

4.6 Full-color Internet fax system (MRC)

   This adds MRC image structures to the previous example.

      (& (image-file-structure=TIFF-MRC)
         (MRC-mode<=1) (MRC-max-stripe-size>=0)
         (| (& (color=binary)
               (| (image-coding=[MH,MR,MMR])
                  (& (image-coding=JBIG)
                     (image-coding-constraint=JBIG-T85)
                     (JBIG-stripe-size=128) ) )
               (| (& (dpi=204) (dpi-xyratio=[204/98,204/196]) )
                  (& (dpi=200) (dpi-xyratio=[200/100,1]) )
                  (& (dpi=[300,400]) (dpi-xyratio=1) ) ) )
            (& (color=limited)
               (| (& (color-space=[Device-RGB,Device-CMY])
                     (color-levels<=8) ) )
               (| (& (color-space=Device-CMYK)
                     (color-levels<=16) ) )
               (image-coding=JBIG)
               (image-coding-constraint=JBIG-T43)



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RFC 2879      Content Feature Schema for Internet Fax (V2)   August 2000


               (JBIG-stripe-size=128)
               (image-interleave=stripe)
               (dpi=[100,200,300,400]) (dpi-xyratio=1) )
            (& (color=mapped)
               (color-levels<=65536)
               (image-coding=JBIG)
               (image-coding-constraint=JBIG-T43)
               (JBIG-stripe-size=128)
               (image-interleave=stripe)
               (color-space=CIELAB)
               (CIELAB-L-min>=0)
               (CIELAB-L-max<=100)
               (CIELAB-a-min>=-85)
               (CIELAB-a-max<=85)
               (CIELAB-b-min>=-75)
               (CIELAB-b-max<=125) ) )
               (color-illuminant=D50)
               (dpi=[100,200,300,400]) (dpi-xyratio=1) )
            (& (color=grey)
               (| (& (image-coding=JPEG)
                     (image-coding-constraint=JPEG-T4E) )
                  (& (image-coding=JBIG)
                     (image-coding-constraint=JBIG-T43)
                     (JBIG-stripe-size=128)
                     (image-interleave=stripe) ) )
               (color-space=CIELAB)
               (color-levels<=256)
               (color-illuminant=D50)
               (CIELAB-L-min>=0)
               (CIELAB-L-max<=100)
               (dpi=[100,200,300,400]) (dpi-xyratio=1) )
            (& (color=full)
               (| (& (image-coding=JPEG)
                     (image-coding-constraint=JPEG-T4E)
                     (color-subsampling=["1:1:1","4:1:1"]) )
                  (& (image-coding=JBIG)
                     (image-coding-constraint=JBIG-T43)
                     (JBIG-stripe-size=128)
                     (image-interleave=stripe) ) )
               (color-levels<=16777216)
               (color-space=CIELAB)
               (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)



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RFC 2879      Content Feature Schema for Internet Fax (V2)   August 2000


               (dpi=[100,200,300,400]) (dpi-xyratio=1) ) )
         (size-x<=2550/254)
         (Paper-size=[Letter,A4,B4])
         (ua-media=stationery) )

4.7 Sender and receiver feature matching

   This example considers sending a document to an enhanced black-and-
   white fax system with the following receiver capabilities:

      (& (| (& (dpi=200) (dpi-xyatio=200/100) )
            (& (dpi=200) (dpi-xyratio=1) )
            (& (dpi=300) (dpi-xyratio=1) )
            (& (dpi=400) (dpi-xyratio=1) ) )
         (color=Binary)
         (| (& (paper-size=A4) (ua-media=[stationery,transparency]) )
            (& (paper-size=B4) (ua-media=continuous) ) )
         (image-coding=[MH,MR,JBIG]) )

   Turning to the document itself, assume it is available to the sender
   in three possible formats, A4 high resolution, B4 low resolution and
   A4 high resolution color, described by:

      (& (dpi=300) (dpi-xyratio=1)
         (color=Binary)
         (paper-size=A4)
         (image-coding=[MMR,JBIG]) )

      (& (dpi=200) (dpi-xyratio=200/100)
         (color=Binary)
         (paper-size=B4)
         (image-coding=[MH,MR]) )

      (& (dpi=300) (dpi-xyratio=1)
         (color=Mapped) (color-levels<=256)
         (paper-size=A4)
         (image-coding=JPEG) )

   These three image formats can be combined into a composite capability
   statement by a logical-OR operation (to describe format-1 OR format-2
   OR format-3):

      (| (& (dpi=300) (dpi-xyratio=1)
            (color=Binary)
            (paper-size=A4)
            (image-coding=[MMR,JBIG]) )
         (& (dpi=200) (dpi-xyratio=200/100)
            (color=Binary)



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RFC 2879      Content Feature Schema for Internet Fax (V2)   August 2000


            (paper-size=B4)
            (image-coding=[MH,MR]) )
         (& (dpi=300) (dpi-xyratio=1)
            (color=Mapped) (color-levels=42)
            (paper-size=A4)
            (image-coding=JPEG) ) )

   This could be simplified, but there is little gain in doing so at
   this point.

   The composite document description can be matched with the receiver
   capability description, according to the rules in [2], to yield the
   result:

      (| (& (dpi=300) (dpi-xyratio=1)
            (color=Binary)
            (paper-size=A4)
            (ua-media=[stationery,transparency])
            (image-coding=JBIG) )
         (& (dpi=200) (dpi-xyratio=200/100)
            (color=Binary)
            (paper-size=B4)
            (ua-media=continuous)
            (image-coding=[MH,MR]) ) )

   Points to note about the feature matching process:

   o  The color document option is eliminated because the receiver
      cannot handle either color (indicated by '(color=Mapped)') or
      JPEG coding (indicated by '(image-coding=JPEG)').

   o  The high resolution version of the document with '(dpi=300)' must
      be send using '(image-coding=JBIG)' because this is the only
      available coding of the image data that the receiver can use for