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'16' Summary: 10 errors (**), 0 flaws (~~), 5 warnings (==), 22 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Fax working group Lloyd McIntyre 3 INTERNET-DRAFT Xerox Corporation 4 Category: Work-in-progress Graham Klyne 5 5GM/Content Technology Ltd 6 September 1998 7 Expires: March 1999 9 Internet fax T.30 Feature Mapping 10 12 Status of this memo 14 This document is an Internet-Draft. Internet-Drafts are working 15 documents of the Internet Engineering Task Force (IETF), its areas, 16 and its working groups. Note that other groups may also distribute 17 working documents as Internet-Drafts. 19 Internet-Drafts are draft documents valid for a maximum of six 20 months and may be updated, replaced, or obsoleted by other 21 documents at any time. It is inappropriate to use Internet-Drafts 22 as reference material or to cite them other than as ``work in 23 progress''. 25 To view the entire list of current Internet-Drafts, please check 26 the "1id-abstracts.txt" listing contained in the Internet-Drafts 27 Shadow Directories on ftp.is.co.za (Africa), ftp.nordu.net 28 (Northern Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au 29 (Pacific Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US 30 West Coast). 32 [[INTENDED STATUS: This memo provides information for the Internet 33 community. It does not specify an Internet standard of any kind. 34 Distribution of this memo is unlimited.]] 36 Copyright Notice 38 Copyright (C) The Internet Society 1998. All Rights Reserved. 40 Abstract 42 This document describes how to map Group 3 fax capability 43 identification bits, described in ITU-T.30 [6], into the Internet 44 fax feature schema described in "Content feature schema for 45 Internet fax" [4]. 47 This is a companion to the fax feature schema document [4], which 48 itself defines a profile of the media feature registration 49 mechanisms [1,2,3], for use in performing capability identification 50 between extended Internet fax systems [5]. 52 RFC nnnn Internet fax T.30 Feature Mapping September 1998 54 Table of contents 56 1. Introduction ............................................3 57 1.1 Organization of this document 3 58 1.2 Terminology and document conventions 3 59 1.3 Revision history 4 60 1.4 Unfinished business 4 61 2. Combining feature tags ..................................4 62 2.1 Relationship to Group 3 fax 4 63 2.2 Feature set descriptions 5 64 2.3 Examples 5 65 2.3.1 Data resource example 5 66 2.3.2 Recipient capabilities example 6 67 3. Survey of media-related T.30 capability bits ............6 68 3.1 DIS/DTC bit 15 (resolution) 6 69 3.2 DIS/DTC bit 16 (MR coding) 6 70 3.3 DIS/DTC bits 17,18 (width) 7 71 3.4 DIS/DTC bits 19,20 (length) 7 72 3.5 DIS/DTC bit 31 (MMR coding) 7 73 3.6 DIS/DTC bit 36 (JBIG multi-level coding) 7 74 3.7 DIS/DTC bit 37 (plane interleave) 7 75 3.8 DIS/DTC bits 41,42,43 (resolution) 8 76 3.9 DIS/DTC bits 44,45 (preferred units) 8 77 3.10 DIS/DTC bit 68 (JPEG) 9 78 3.11 DIS/DTC bit 69 (colour) 9 79 3.12 DIS/DTC bit 71 (bits/pixel) 9 80 3.13 DIS/DTC bit 73 (no subsampling) 9 81 3.14 DIS/DTC bit 74 (custom illuminant) 9 82 3.15 DIS/DTC bit 75 (custom gamut) 10 83 3.16 DIS/DTC bits 76,77 (paper size) 10 84 3.17 DIS/DTC bits 78,79 (JBIG bi-level coding) 10 85 3.18 DIS/DTC bit 92,93,94 (MRC level) 10 86 3.19 DIS/DTC bit 95 (MRC strip size) 11 87 3.20 DIS/DTC bit 97 (resolution) 11 88 3.21 DIS/DTC bit 98 (resolution) 11 89 4. Summary of T.30 capability dependencies .................11 90 4.1 Image coding 11 91 4.1.1 Bi-level coding 12 92 4.1.2 Multi-level coding 12 93 4.1.3 MRC coding 13 94 4.2 Resolution and units 13 95 4.3 Colour capabilities 15 96 4.4 Document size 15 97 5. Mapping T.30 capabilities to fax feature schema .........16 98 6. Example .................................................16 99 7. Security considerations .................................16 100 8. Full copyright statement ................................16 101 9. Acknowledgements ........................................17 102 10. References .............................................17 103 11. Authors' addresses .....................................18 105 RFC nnnn Internet fax T.30 Feature Mapping September 1998 107 1. Introduction 109 This document describes how to map Group 3 fax capability 110 identification bits, described in ITU-T.30 [6], into the Internet 111 fax feature schema described in "Content feature schema for 112 Internet fax" [4]. 114 This is a companion to the fax feature schema document [4], which 115 itself defines a profile of the media feature registration 116 mechanisms [1,2,3], for use in performing capability identification 117 between extended Internet fax systems [5]. 119 1.1 Organization of this document 121 Section 2 introduces the mechanisms that combine feature tag 122 constraints to describe complex recipient capabilities. 124 Section 3 surveys Group 3 fax (T.30) capability bits that relate to 125 media handling capabilities, and indicates corresponding feature 126 tags used to describe equivalent capabilities of an eifax system. 128 Setion 4 describes the dependencies between Group 3 fax (T.30) 129 capability bits. These are presented in a decision table format 130 [16] with descriptive text in place of the action bodies. 132 Section 5 describes a formal mechanism for converting Group 3 fax 133 (T.30) capability masks to fax feature schema statements. The 134 conversion process is driven by the decision tables introduced 135 previously, using fax feature feature schema statements and 136 combining rules in the action bodies. 138 Section 6 presents a fairly complex example of a Group 3 fax (T.30) 139 capability mask, and uses the formal mechanism described previously 140 to convert that into a corresponding fax feature schema statement. 142 1.2 Terminology and document conventions 144 eifax system 145 is used to describe any software, device or combination 146 of these that conforms to the specification "Extended 147 Facsimile Using Internet Mail" [5]. 149 Feature is used as defined in [15]. (See also section 2 of this 150 memo.) 152 Feature tag 153 is used as defined in [15]. (See also section 2.) 155 Feature collection 156 is used as defined in [2]. (See also section 2.) 158 RFC nnnn Internet fax T.30 Feature Mapping September 1998 160 Feature set 161 is used as defined in [2]. (See also section 2.) 163 1.3 Revision history 165 00a 29-Sep-1998 Initial draft. 167 1.4 Unfinished business 169 . Section 5: T.30 to fax schema conversion 171 . Section 6: example 173 . Update references when available: 174 Complete G3fax references 176 2. Combining feature tags 178 A fax document can be described by media features. Any single 179 media feature value can be thought of as just one component of a 180 feature collection that describes some instance of a document (e.g. 181 a printed fax, a displayed image, etc.). Such a feature collection 182 consists of a number of media feature tags (each per [1]) and 183 associated feature values. 185 A feature set contains a number of feature collections. Thus, a 186 feature set can describe a number of different fax document 187 instances. These can correspond to different treatments of a 188 single document (e.g. different resolutions used for printing a 189 given fax), a number of different documents subjected to a common 190 treatment (e.g. the range of different images that can be rendered 191 on a given display), or some combination of these (see examples 192 below). 194 Thus, a description of a feature set can describe the rendering 195 requirements of a fax document or the capabilities of a receiving 196 eifax system. 198 2.1 Relationship to Group 3 fax 200 A "feature tag" can be compared with a single bit in a T.30 DCS 201 frame, describing a specific attribute of a specific fax document. 203 A "feature collection" corresponds to a complete T.30 DCS frame, 204 describing a range of attributes of a specific fax document. 206 A "feature set" corresponds to a DIS or DTC frame, describing the 207 range of document attributes that can be accepted by a given fax 208 machine. 210 RFC nnnn Internet fax T.30 Feature Mapping September 1998 212 Within T.30 DIS/DTC frames, dependencies between the various 213 capabilities are implicit in the definitions of the capabilities. 214 E.g. multi-level coding (DIS/DTC bit 68) requires support for 215 200*200dpi resolution (DIS/DTC bit 15). In the feature set 216 description framework used by eifax systems [1,2,3,4] such 217 dependencies between different features are expressed explicitly. 218 Later sections of this memo describe how the implicit dependencies 219 of T.30 are expressed using the media feature set notation. 221 2.2 Feature set descriptions 223 The general approach to describing feature sets, described more 224 fully in [2], is use functions ("predicates") that, when applied to 225 a feature collection value, yield a Boolean value that is TRUE if 226 the feature collection describes an acceptable fax document 227 instance, otherwise FALSE. 229 P(F) 230 P(F) = TRUE <- : -> P(F) = FALSE 231 : 232 +----------:----------+ This box represents some 233 | : | universe of fax documents (F) 234 | Included : Excluded | from which some acceptable subset 235 | : | is selected by the predicate P. 236 +----------:----------+ 237 : 239 2.3 Examples 241 In the examples below the following notation is used: 243 (x ? y) tests feature tag 'x' for some relationship 244 with value 'y'. 246 (| p1 p2 ... pn ) represents the logical-OR of predicates 'p1', 247 'p2' up to 'pn'. 249 (& p1 p2 ... pn ) represents the logical-AND of predicates 250 'p1', 'p2' up to 'pn'. 252 2.3.1 Data resource example 254 The following expression uses the syntax of [x] to describe a data 255 resource that can be displayed either: 256 (a) as a 750x500 pixel image using 15 colours, or 257 (b) at 150dpi on an A4 page. 259 (| (& (pix-x=750) (pix-y=500) (color=15) ) 260 (& (dpi>=150) (papersize=iso-A4) ) ) 262 RFC nnnn Internet fax T.30 Feature Mapping September 1998 264 2.3.2 Recipient capabilities example 266 The following expression describes a receiving system that has: 267 (a) a screen capable of displaying 640*480 pixels and 16 million 268 colours (24 bits per pixel), 800*600 pixels and 64 thousand 269 colours (16 bits per pixel) or 1024*768 pixels and 256 colours 270 (8 bits per pixel), or 271 (b) a printer capable of rendering 300dpi on A4 paper. 273 (| (& (| (& (pix-x<=640) (pix-y<=480) (color<=16777216) ) 274 (& (pix-x<=800) (pix-y<=600) (color<=65535) ) 275 (& (pix-x<=1024) (pix-y<=768) (color<=256) ) ) 276 (media=screen) ) 277 (& (dpi=300) 278 (media=stationery) (papersize=iso-A4) ) ) 280 3. Survey of media-related T.30 capability bits 282 The following sections refer to T.30 DIS/DTC bits identified and 283 described in Table 2/T.30 and accompanying notes. Bit numbers that 284 are not referenced below are considered to be not related to media 285 features, hence not relevant to the Internet fax feature schema. 287 NOTE: some of the DIS/DTC bits identified below are 288 documented in revisions of the T.30 specification that 289 are not yet publicly available from the ITU. 291 3.1 DIS/DTC bit 15 (resolution) 293 All Group 3 fax systems are required to support a basic resolution 294 of 200*100dpi (dots per inch) or 8*3.85dpmm (dots per millimetre). 296 Setting this bit indicates additional support for 200*200dpi or 297 8*7.7dpmm. 299 See also: bits 44,45. 301 3.2 DIS/DTC bit 16 (MR coding) 303 All Group 3 fax systems are required to support Modified Huffman 304 (MH) 1-dimensional coding for bi-level images. (A bi-level image 305 is one with just two pixel states such as black and white, as 306 opposed to a grey-scale or colour image.) 308 Setting this bit indicates additional support for Modified Read 309 (MR) 2-dimensional coding for bi-level images. 311 Both MH and MR coding are described in ITU T.4 [7]. 313 See also: bits 31,78,79. 315 RFC nnnn Internet fax T.30 Feature Mapping September 1998 317 3.3 DIS/DTC bits 17,18 (width) 319 All Group 3 fax systems are required to support 215mm paper width. 320 These bits can be set to indicate additional support for 255mm and 321 303mm paper widths. 323 See also: bits 76,77. 325 3.4 DIS/DTC bits 19,20 (length) 327 All Group 3 fax systems are required to support 297mm paper length. 328 These bits can be set to indicate additional support for 364mm and 329 unlimited paper lengths. 331 See also: bits 76,77. 333 3.5 DIS/DTC bit 31 (MMR coding) 335 Setting this bit indicates support for Modified Read (MR) 2- 336 dimensional coding for bi-level images, in addition to the required 337 support for MH coding. 339 MMR coding is described in ITU T.6 [8]. 341 See also: bits 6,78,79. 343 3.6 DIS/DTC bit 36 (JBIG multi-level coding) 345 Setting this bit indicates support for JBIG lossless coding for 346 multi-level images. 348 JBIG coding for multi-level images is described in ITU T.43 [10]. 350 See also: bits 68,69. 352 3.7 DIS/DTC bit 37 (plane interleave) 354 Setting this bit indicates support for plane interleave for JBIG- 355 coded multi-level images, in addition to stripe interleave coding. 357 JBIG coding for multi-level images is described in ITU T.43 [10]. 359 [[[Is this reference appropriate?]]] 361 See also: bit 36. 363 RFC nnnn Internet fax T.30 Feature Mapping September 1998 365 3.8 DIS/DTC bits 41,42,43 (resolution) 367 Setting these bits indicates support for resolutions in addition to 368 100*200dpi and 200*200dpi, or 8*3.85dpmm and 8*7.7dpmm. 370 Bit 41 indicates support for 8*15.4dpmm bi-level images 371 (independently of the settings of bits 44 and 45). 373 Bit 42 indicates support for 300*300dpi bi-level images 374 (independently of the settings of bits 44 and 45). 376 [[[Also applies to multi-level images or MRC mask if bit 377 97 is set???]]] 379 Bit 43 indicates support for 400*400dpi and/or 16*15.4dpmm bi-level 380 images, depending uppon the settings of bits 44 and 45. 382 [[[Also applies to multi-level images or MRC mask if bit 383 97 is set???]]] 385 See also: bits 44,45,97. 387 3.9 DIS/DTC bits 44,45 (preferred units) 389 These bits are used to indicate the preferred resolution units for 390 received images. Because the exact resolution and x/y pixel 391 density measures in dpi or dpmm are slightly different, some image 392 size and aspect ratio distortion may occur if the sender and 393 receiver use different units. 395 Even when sender and recipient have different preferred units, 396 image transfer must be accomplished. For most fax uses, the dpi 397 and dpmm measurements are sufficiently close to each other that the 398 difference is not noticed. 400 The preferred units setting affects the interpretation of the 401 following resolutions: 403 dpi dpmm 404 --- ---- 405 Base 200*100 8*3.85 406 Bit 15 200*200 8*7.7 407 Bit 43 400*400 16*15.4 409 See also: bits 15, 43 411 RFC nnnn Internet fax T.30 Feature Mapping September 1998 413 3.10 DIS/DTC bit 68 (JPEG) 415 This bit indicates support for JPEG coding of multi-level images. 417 JPEG coding for multi-level images is described in ITU T.81 [12]. 419 See also: bits 15,36,69,73 421 3.11 DIS/DTC bit 69 (colour) 423 This bit indicates support for multi-level colour images, as 424 opposed to just grey-scale. 426 See also: bits 36,68,73. 428 3.12 DIS/DTC bit 71 (bits/pixel) 430 Standard support for multi-level images uses 8 bits per pixel. 431 Setting this bit indicates additional support for 12 bits per 432 pixel. 434 See also: bit 68. 436 3.13 DIS/DTC bit 73 (no subsampling) 438 Standard support for multi-level images uses 4:1:1 chrominance 439 subsampling. That is, for each 4 luminance samples in the image 440 description there is a single chrominance sample. 442 Setting this bit indicates that colour images without subsampling 443 can also be supported. 445 See also: bits 36,68,69. 447 3.14 DIS/DTC bit 74 (custom illuminant) 449 Setting this bit indicates that a custom illuminant can be 450 supported for multi-level images. 452 [[[Including grey-scale?]]] 454 Use of a custom illuminant with multi-level images is described in 455 ITU T.42 [9]. 457 See also: bit 68. 459 RFC nnnn Internet fax T.30 Feature Mapping September 1998 461 3.15 DIS/DTC bit 75 (custom gamut) 463 Setting this bit indicates that a custom gamut can be supported for 464 multi-level images. 466 [[[Including grey-scale?]]] 468 Use of a custom gamut with multi-level images is described in ITU 469 T.42 [9]. 471 See also: bit 68. 473 3.16 DIS/DTC bits 76,77 (paper size) 475 All Group 3 faxes are required to support A4 paper size. These 476 bits can be set to indicate additional support for North American 477 letter and legal paper sizes. 479 See also: bits 17,18,19,20. 481 3.17 DIS/DTC bits 78,79 (JBIG bi-level coding) 483 Setting bit 78 indicates support for JBIG coding of bi-level 484 images, in addition to the required support for MH coding. 486 Setting bits 78 and 79 indicates additional support for using 487 optional 'LO' with JBIG coded bi-level images. Basic bi-level JBIG 488 coding uses 128 lines per stripe; the 'LO' option allows other 489 values to be used. 491 JBIG coding of bi-level images is described in ITU-T.85 [14]. 493 See also: bits 16,31. 495 3.18 DIS/DTC bit 92,93,94 (MRC level) 497 If these bits are all zero, then Mixed Raster Content (MRC) coding 498 is not supported. Otherwise, they represent a number in the range 499 1-7 that indicates an MRC capability level. 501 MRC coding of images is described in ITU-T.44 [11]. 503 See also: bit 95. 505 RFC nnnn Internet fax T.30 Feature Mapping September 1998 507 3.19 DIS/DTC bit 95 (MRC strip size) 509 If bits 92-94 inducate an MRC coding capability, then this bit 510 indicates the maximum strip size. If zero, the maximum strip size 511 is 256 lines, otherwise the maximum strip size is a full page. 513 MRC coding of images is described in ITU-T.44 [11]. 515 See also: bits 92,93,94. 517 3.20 DIS/DTC bit 97 (resolution) 519 Setting this bit indicates that the additional resolutions 520 indicated by bits 42 and 43 may be used for multi-level images and 521 any MRC mask layer. 523 See also: bits 42,43,68. 525 3.21 DIS/DTC bit 98 (resolution) 527 Setting this bit indicates that the additional resolution 528 100*100dpi may be used for multi-level images and any MRC mask 529 layer. 531 See also: bit 68. 533 4. Summary of T.30 capability dependencies 535 This section contains a number of decision tables that indicate the 536 allowable combinations of T.30 DIS/DTC mask bits. 538 Within the decision table bodies, the following symbols are use to 539 indicate values of T.30 DIS/DTC bits: 541 0 = bit set to '0' 542 1 = bit set to '1' 543 x = don't care bit value: may be '0' or '1' 544 *0 = bit must be '0' ('1' is invalid in given combination) 545 *1 = bit must be '1' ('0' is invalid in given combination) 546 # = bits in row combined to form a numeric value 548 4.1 Image coding 550 MH coding is required as a minimum for Group 3 fax operation. 552 RFC nnnn Internet fax T.30 Feature Mapping September 1998 554 4.1.1 Bi-level coding 556 <------- T.30 bits ---------> 557 15|16|31|36|37|68|69|73|78|79||Description 558 --+--+--+--+--+--+--+--+--+--++--------------------------------------- 559 x| 0| 0| | | | | | 0| 0||Compression = [MH] 560 x| 1| 0| | | | | | 0| 0||Compression = [MH,MR] 561 x| 0| 1| | | | | | 0| 0||Compression = [MH,MMR] 562 x| 1| 1| | | | | | 0| 0||Compression = [MH,MR,MMR] 563 x| 0| 0| | | | | | 1| 0||Compression = [MH,T.85] 564 x| 1| 0| | | | | | 1| 0||Compression = [MH,MR,T.85] 565 x| 0| 1| | | | | | 1| 0||Compression = [MH,MMR,T.85] 566 x| 1| 1| | | | | | 1| 0||Compression = [MH,MR,MMR,T.85] 567 x| 0| 0| | | | | |*1| 1||Compression = [MH,T.85,T.85LO] 568 x| 1| 0| | | | | |*1| 1||Compression = [MH,MR,T.85,T.85LO] 569 x| 0| 1| | | | | |*1| 1||Compression = [MH,MMR,T.85,T.85LO] 570 x| 1| 1| | | | | |*1| 1||Compression = [MH,MR,MMR,T.85,T.85LO] 571 | | | | | | | | | ||MH = 1-D per T.4 572 | | | | | | | | | ||MR = 2-D per T.4 573 | | | | | | | | | ||MMR = 2-D per T.6 574 | | | | | | | | | ||T.85 = Basic JBIG per T.85 575 | | | | | | | | | ||T.85LO = Optional LO with T.85/JBIG 576 --+--+--+--+--+--+--+--+--+--++--------------------------------------- 578 4.1.2 Multi-level coding 580 Note: When 37, 69, 73, 79 and 95 are set to "1", the feature 581 represented by "0" is also available. Example: If plane interleave 582 is available then stripe interleave is also available. 584 <------- T.30 bits ---------> 585 15|16|31|36|37|68|69|73|78|79||Description 586 --+--+--+--+--+--+--+--+--+--++--------------------------------------- 587 x| | |*0| x| 0| x| x| | ||No grey or colour (no T.43 or JPEG) 588 *1| | | 0| x| 1| 0| x| | ||JPEG, grey scale only 589 *1| | | 0| x| 1| 1| 0| | ||JPEG, full colour, subsampling 590 *1| | | 0| x| 1| 1| 1| | ||JPEG, full colour, no subsampling 591 *1| | | 1| 0| 1| 0| x| | ||T.43, JPEG, grey only, stripe i/l 592 *1| | | 1| 1| 1| 0| x| | ||T.43, JPEG, grey only, plane i/l 593 *1| | | 1| 0| 1| 1| 0| | ||T.43, JPEG, colour, stripe i/l, s/s 594 *1| | | 1| 0| 1| 1| 1| | ||T.43, JPEG, colour, stripe i/l, no s/s 595 *1| | | 1| 1| 1| 1| 0| | ||T.43, JPEG, colour, plane i/l, s/s 596 *1| | | 1| 1| 1| 1| 1| | ||T.43, JPEG, colour, plane i/l, no s/s 597 | | | | | | | | | ||'s/s' is 4:1:1 L*:a*:b* subsampling 598 | | | | | | | | | ||'No s/s' is 1:1:1 L*:a*:b* subsampling 599 | | | | | | | | | ||'stripe i/l' is stripe interleave 600 | | | | | | | | | ||'plane i/l' is full-plane interleave 601 --+--+--+--+--+--+--+--+--+--++--------------------------------------- 602 RFC nnnn Internet fax T.30 Feature Mapping September 1998 604 4.1.3 MRC coding 606 Multi-level coders, as indicated above, are used within an MRC- 607 coded image. 609 <---- T.30 bits ------> 610 15|92|93|94|95| | | ||Description 611 --+--+--+--+--+--+--+--++--------------------------------------- 612 x| 0| 0| 0| x| | | ||MRC not accepted 613 *1| #| #| #| 0| | | ||MRC level, max strip 256 lines 614 *1| #| #| #| 1| | | ||MRC level, max strip full page 615 | | | | | | | ||### is MRC performance level (1-7, per T.44) 616 --+--+--+--+--+--+--+--++--------------------------------------- 618 4.2 Resolution and units 620 Support for bi-level coding at least one of 200*100dpi or 621 8*3.85dpmm is required in all cases for Group 3 fax conformance. 622 For multi-level coders (colour/grey) the base resolution is 623 200*200dpi (i.e. bit 15 must be set). 625 When multi-level coders (JPEG or T.43) are used, only inch-based 626 square resolutions are available. However, the base non-square 627 resolution (i.e. 200x100dpi or 8x3.85dpmm) must still be available 628 as a capability for use with the mandatory bi-level coder (MH). 629 Hence, any references to metric and non-square resolutions in the 630 table below apply only to bi-level coders. 632 In the following table: 633 dpi = dots per inch 634 dpmm = dots per millimetre 636 RFC nnnn Internet fax T.30 Feature Mapping September 1998 638 <------- T.30 bits ------> 639 15|41|42|43|44|45|68|97|98||Description 640 --+--+--+--+--+--+--+--+--++----------------------------------------- 641 0| | | 0| x| x| | | ||Resolution = base only 642 | | | | | | | | || 643 1| | | 0| 0| 0| | | ||Invalid 644 1| | | 0| 0| 1| | | ||Resolution = 8*3.85dpmm or 8*7.7dpmm 645 1| | | 0| 1| 0| | | ||Resolution = 200*100dpi or 200*200dpi 646 1| | | 0| 1| 1| | | ||Resolution = 8*3.85dpmm or 8*7.7dpmm 647 | | | | | | | | || or 200*100dpi or 200*200dpi 648 | | | | | | | | || 649 0| | | 1| 0| 0| | | ||Invalid 650 0| | | 1| 0| 1| | | ||Resolution = 8*3.85dpmm or 16*15.4dpmm 651 0| | | 1| 1| 0| | | ||Resolution = 200*100dpi or 400*400dpi 652 0| | | 1| 1| 1| | | ||Resolution = 8*3.85dpmm or 16*15.4dpmm 653 | | | | | | | | || or 200*100dpi or 400*400dpi 654 | | | | | | | | || 655 1| | | 1| 0| 0| | | ||Invalid 656 1| | | 1| 0| 1| | | ||Resolution = 8*3.85dpmm or 8*7.7dpmm 657 | | | | | | | | || or 16*15.4dpmm 658 1| | | 1| 1| 0| | | ||Resolution = 200*100dpi or 200*200dpi 659 | | | | | | | | || or 400*400dpi 660 1| | | 1| 1| 1| | | ||Resolution = 8*7.7dpmm or 8*7.7dpmm 661 | | | | | | | | || or 16*15.4dpmm 662 | | | | | | | | || or 200*100dpi or 200*200dpi 663 | | | | | | | | || or 400*400dpi 664 --+--+--+--+--+--+--+--+--++----------------------------------------- 665 | 0| | | | | | | ||Resolutions as above 666 | 1| | | x| x| | | ||Also supports 8*15.4dpmm (bi-level only) 667 | | | | | | | | ||Independent of bits 44,45 668 --+--+--+--+--+--+--+--+--++----------------------------------------- 669 | | 0| | | | | | ||Resolutions as above 670 | | 1| | x| x| | | ||Also supports 300*300dpi 671 | | | | | | | | ||Independent of bits 44,45 672 --+--+--+--+--+--+--+--+--++----------------------------------------- 673 | | | | | | x| 0| ||Resolutions as above 674 | | | | | |*1| 1| ||Also 300*300dpi or 400*400dpi (see below) 675 | | | | | | | | ||(Applies colour, grey-scale or MRC mask) 676 | | | | | | | | ||(Valid only when bit 42 or 43 is set.) 677 | | | | | | | | ||(42 => 300dpi, 43=>400dpi) 678 --+--+--+--+--+--+--+--+--++----------------------------------------- 679 | | | | | | x| | 0||Resolutions as above 680 | | | | x| x|*1| | 1||Also 100*100dpi 681 | | | | | | | | ||(Applies colour, grey-scale or MRC only) 682 | | | | | | | | ||Independent of bits 44,45 683 --+--+--+--+--+--+--+--+--++----------------------------------------- 684 RFC nnnn Internet fax T.30 Feature Mapping September 1998 686 4.3 Colour capabilities 688 Bit 68 (JPEG) is required for any colour/grey scale mode, and bit 689 36 indicates additional T.43 capability. 691 <------- T.30 bits ---> 692 36|68|69|71|74|75| | ||Description 693 --+--+--+--+--+--+--+--++----------------------------------------- 694 0| 0| x| x| x| x| | ||No grey scale or colour 695 x| 1| 0| | | | | ||Grey scale only 696 0| 1| 1| | | | | ||Full colour capability (CIE L*a*b*) 697 1| 1| 1| | | | | ||Full colour capability: 698 | | | | | | | || (CIE L*a*b*, palette, RGB 1 bit/colour 699 | | | | | | | || and CMY(K)1 bit/colour) 700 --+--+--+--+--+--+--+--++----------------------------------------- 701 x| 1| | 0| | | | ||8 bits/pixel 702 x| 1| | 1| | | | ||8 or 12 bits/pixel 703 --+--+--+--+--+--+--+--++----------------------------------------- 704 x| 1| | | 0| | | ||CIE standard illuminant D50 (per T.42) 705 x| 1| | | 1| | | ||Custom illuminants (definition provided) 706 --+--+--+--+--+--+--+--++----------------------------------------- 707 x| 1| | | | 0| | ||Default gamut (per T.42) 708 x| 1| | | | 1| | ||Custom gamuts (definition provided) 709 --+--+--+--+--+--+--+--++----------------------------------------- 711 4.4 Document size 713 A4 width (215mm) is required as a minimum for Group 3 fax 714 conformance. A Group 3 fax machine must always be able to receive 715 an A4 image. 717 <---- T.30 bits ------> 718 17|18|19|20|76|77| | ||Description (later to be media features) 719 --+--+--+--+--+--+--+--++----------------------------------------- 720 0| 0| | | | | | ||Width = 215mm 721 1| 0| | | | | | ||Width = 215mm or 255mm 722 0| 1| | | | | | ||Width = 215mm, 255mm or 303mm 723 1| 1| | | | | | ||Invalid - interpret as (17=0,18=1) 724 | | | | | | | ||(measurements described as scan line length) 725 | | | | | | | ||(corresp. inch measurements: T.4 sect 2.2) 726 --+--+--+--+--+--+--+--++----------------------------------------- 727 | | 0| 0| | | | ||Length = 297mm (A4) 728 | | 1| 0| | | | ||Length = 297mm (A4) or 364mm (B4) 729 | | 0| 1| | | | ||Length = unlimited 730 | | 1| 1| | | | ||Invalid 731 --+--+--+--+--+--+--+--++----------------------------------------- 732 | | | | 0| 0| | ||Papersize = A4 733 | | | | 1| 0| | ||Papersize = A4 or NA-Letter 734 | | | | 0| 1| | ||Papersize = A4 or NA-Legal 735 | | | | 1| 1| | ||Papersize = A4 or NA-Letter or NA-Legal 736 --+--+--+--+--+--+--+--++----------------------------------------- 737 RFC nnnn Internet fax T.30 Feature Mapping September 1998 739 5. Mapping T.30 capabilities to fax feature schema 741 [[[This would be a more formal treatment of the material in section 742 4, describing how to map various combinations of T.30 bits into the 743 fax feature schema using a number of decision tables containing fax 744 feature schema statements, and some formal combining rules using 745 the conneg -algebra- format.]]] 747 6. Example 749 [[[I am proposing a single example that starts with a fairly 750 complex T.30 capability mask, and maps that into the corresponding 751 fax-schema feature set expression]]] 753 7. Security considerations 755 Security considerations are discussed in the fax feature schema 756 description [4]. This memo is not believed to introduce any 757 additional security concerns. 759 8. Full copyright statement 761 Copyright (C) The Internet Society 1998. All Rights Reserved. 763 This document and translations of it may be copied and furnished to 764 others, and derivative works that comment on or otherwise explain 765 it or assist in its implementation may be prepared, copied, 766 published and distributed, in whole or in part, without restriction 767 of any kind, provided that the above copyright notice and this 768 paragraph are included on all such copies and derivative works. 769 However, this document itself may not be modified in any way, such 770 as by removing the copyright notice or references to the Internet 771 Society or other Internet organizations, except as needed for the 772 purpose of developing Internet standards in which case the 773 procedures for copyrights defined in the Internet Standards process 774 must be followed, or as required to translate it into languages 775 other than English. 777 The limited permissions granted above are perpetual and will not be 778 revoked by the Internet Society or its successors or assigns. 780 RFC nnnn Internet fax T.30 Feature Mapping September 1998 782 This document and the information contained herein is provided on 783 an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET 784 ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR 785 IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF 786 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 787 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 789 9. Acknowledgements 791 The authors gratefully ackowledge the following persons who made 792 comments on earlier versions of this memo: Mr. Hiroshi Tamura, 793 [[...]]. 795 10. References 797 [1] "Media Feature Tag Registration Procedure" 798 Koen Holtman, TUE 799 Andrew Mutz, Hewlett-Packard 800 Ted Hardie, NASA 801 Internet draft: 802 Work in progress, July 1998. 804 [2] "A syntax for describing media feature sets" 805 Graham Klyne, 5GM/Content Technologies 806 Internet draft: " 807 Work in progress, September 1998. 809 [3] "Media Features for Display, Print, and Fax" 810 Larry Masinter, Xerox PARC 811 Koen Holtman, TUE 812 Andrew Mutz, Hewlett-Packard 813 Dan Wing, Cisco Systems 814 Internet draft: 815 Work in progress, September 1998. 817 [4] "Content feature schema for Internet fax" 818 Lloyd McIntyre, Xerox Corporation 819 Graham Klyne, 5GM/Content Technologies 820 Internet draft: 821 Work in progress, August 1998. 823 [5] "Extended Facsimile Using Internet Mail 824 Larry Masinter, Xerox Corporation 825 Dan Wing, Cisco Systems 826 Internet draft: 827 Work in progress, September 1998. 829 RFC nnnn Internet fax T.30 Feature Mapping September 1998 831 [6] "Procedures for document facsimile transmission in the general 832 switched telephone network" 833 ITU-T Recommendation T.30 834 International Telecommunications Union 835 July 1996 837 [7] T.4 (basic fax coding formats: MH, MR) 839 [8] T.6 (extended 2-D fax coding format: MMR) 841 [9] T.42 (custom illuminant, gamut) 843 [10] T.43 (JBIG for colour/grey) 845 [11] T.44 (MRC) 847 [12] T.81 (JPEG) 849 [13] T.82 (JBIG?????????) 851 [14] T.85 (bi-level JBIG) 853 [15] "Requirements for protocol-independent content negotiation" 854 G. Klyne, Integralis Ltd. 855 Internet draft: 856 Work in progress, March 1998. 858 [16] "Programs from Decision Tables" 859 E. Humbey 860 Macdonald/American Elsevier computer monographs (19), 1973 861 ISBN 0-444-19569-6/0-356-04126-3 863 (This is an old title, and may not be still in print. It 864 contains a number of references to decision table articles 865 published in Communications of the ACM: August 1967, September 866 1970, January 1966, November 1966, October 1968, January 1965, 867 February 1964, June 1970, November 1965, June 1965, February 868 1971.) 870 11. Authors' addresses 872 Lloyd McIntyre 873 Xerox Corporation 874 Mailstop PAHV-305 875 3400 Hillview Ave. 876 Palo Alto, CA 94304 USA 877 Telephone: +1-650-813-6762 878 Facsimile: +1-650-845-2340 879 E-mail: Lloyd.McIntyre@pahv.xerox.com 881 RFC nnnn Internet fax T.30 Feature Mapping September 1998 883 Graham Klyne 884 5th Generation Messaging Ltd. Content Technologies Ltd. 885 5 Watlington Street Forum 1, Station Road 886 Nettlebed Theale 887 Henley-on-Thames, RG9 5AB Reading, RG7 4RA 888 United Kingdom United Kingdom. 889 Telephone: +44 1491 641 641 +44 118 930 1300 890 Facsimile: +44 1491 641 611 +44 118 930 1301 891 E-mail: GK@ACM.ORG