1、STD-ITU-T RECMN T-85-ENGL 1797 m 4b2591 Ob3355b 373 m INTERNATIONAL TELECOMMUN ICATION UN ION I ITU-T TELECOMMUN ICATION STANDARDIZATION SECTOR OF ITU T.85 Corrigendum I (02197) SERIES T: TERMINALS FOR TELEMATIC SERVICES Application profile for Recommendation T.82 - Progressive bi-level image compre
2、ssion (JBIG coding scheme) for facsimile apparatus Corrigendum 1 ITU-T Recommendation T.85 - Corrigendum 1 (Previously CCITT Recommendation) ITU-T T-SERIES RECOMMENDATIONS TERMINALS FOR TELEMATIC SERVICES For further details, please refer to ITU-T List of Recommendations. STD-ITU-T RECMN T.85-ENGL 1
3、997 = 48b2571 Ob33558 144 = FOREWORD The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (IT). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommen- dations on them with a view to stand
4、ardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the IT-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by t
5、he Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, 1993, revised Geneva, 1996). Corrigendum 1 to IT-T Recommendation T.85 was prepared by IT-T Study Group 8 (1993-1996) and was approved on the 13th of February 1997. NOTE In this Recommendation, the expr
6、ession ?Administration? is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. O ITU 1997 Ali rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopyi
7、ng and microfilm, without permission in writing from the ITU. Recommendation T.85Kor.l (02/97) 1 STD-ITU-T RECMN T-85-ENGL 1797 48b2591 Ob33557 OBCI = CONTENTS Page 1 1) Modi 4.4 and add a new subclause 4.5 as follows 2) Modi Appendix I as follows . 1 Appendix I - Examples of the usage of NEWLEN mar
8、ker segment . 3) Add Appendix II as follows . 3 of clause 3 “Principle“ of this Recommendation . 1 Appendix II - The bit order of Coded Data Transmission on communication line conforming to the description 3 11 Recommendation T.85Kor.l (02/97) STD-ITU-T RECMN T. 85-ENGL Corrigendum 1 to Recommendati
9、on T.85 APPLICATION PROFILE FOR RECOMMENDATION T.82 - PROGRESSIVE BI-LEVEL IMAGE COMPRESSION (JBIG CODING SCHEME) FOR FACSIMILE APPARATUS CORRIGENDUM 1 (Geneva, 199 7) 1) Modify 4.4 and add a new subclause 4.5 as follows: 4.4 Usage of the marker segment COMMENT - The interpretation of the informatio
10、n transmitted by COMMENT marker segment depends on the implementation of both ends. NEWLEN - To enable a page length to be changed using a T.82 NEWLEN marker in front of a “null” stripe (e.g. in BASIC mode-2 or OPTION mode): 1) The NEWLEN marker in front of a “null” stripe shall be the first marker
11、in fiont of any such “null” stripe. 2) The T.82 header bit VLENGTH must be set to “1” and the decoder must look beyond the SDRST/SDNORM at the end of all stripes, in order to find any immediately following NEWLEN marker that is in front of a “null” stripe. If such a NEWLEN marker is found, all previ
12、ous values of LO and YD are to be cleared and YD set to equal NEWLEN. 4.5 Initialization of the arithmetic coderldecoder and adaptive templates status At the top of each page of facsimile transmission, the state of arithmetic codeddecoder and adaptive template shall be initialized. 2) Modify Appendi
13、x I as follows: Appendix I Examples of the usage of NEWLEN marker segment This Appendix describes examples of the usage of NEWLEN marker segment for the case when the facsimile terminal cannot identi the vertical size YD of the page to be transmitted when it starts coding. This Appendix applies to t
14、he single-progression sequential coding described in clause 4. The examples shown in this Appendix illustrate the application of 6.2.6.2m.82. 1.1 BASIC mode The first two examples show the case when one page of 500 lines is transmitted in BASIC mode with LO = 128. One page is coded into multiple str
15、ipes with the condition that the vertical length of the page is unknown when the transmitting facsimile terminal starts coding. For the first example, YD is set to Oxffffffff. Then, at the line of 500, the image data exhausts. Recommendation T.8YCor.l (02/97) 1 STD-ITU-T RECMN T-BFI-ENGL 1997 D 48b2
16、59L Ob335bZ 739 D Data stream for BASIC mode-1 BIH (YD = Oxffffffff, LO = 128, VLENGTH = 1 - Other parameters shall be set appropriately). Encoded image data of the fist stripe (line 1-128). ESC, SDNORM. Encoded image data of the second stripe (line 129-256). ESC, SDNORM. Encoded image data of the t
17、hird stripe (line 257-384). ESC, SDNORM. ESC, NEWLEN, New YD (= 500). Encoded image data of the fourth stripe (line 385-500). ESC, SDNORM or SDRST. The following data stream is an example, where the length of the page is not know before coding the last stripe. Note that this case requires the use of
18、 a “null” stripe. This example will also illustrate an estimate of page length that is not the maximum possible (e.g. YD = 1024 = 0x00000400). Data stream for BASIC mode-2 BIH (YD = 0x00000400, LO = 128, VLENGTH =1 - Other parameters shall be set appropriately). Encoded image data of the first strip
19、e (line 1-128). ESC, SDNORM. Encoded image data of the second stripe (line 129-256). ESC, SDNORM. Encoded image data of the third stripe (line 257-384). ESC, SDNORM. Encoded image data of the fowih stripe (line 385-500). ESC, SDNORM. ESC, NEWLEN (note that this is first marker), New YD (= 500). Enco
20、ded data of the fifth stripe (note that “null” means there is no data). ESC, SDNORM or SDRST. 1.2 OPTION mode This example shows the case of “one stripe per page” (also requires an “added” null stripe) transmission in OPTION mode. This optional mode can only be used following a successful negotiatio
21、n. Note that a coder or decoder that cannot support the actual smpe size may have to terminate the call. At the beginning of encoding, as the vertical length of the page is undetermined, YD is set to the maximum value, YD = Oxffffffff (one possible choice). As the stripe size is also undetermined, L
22、O is set to the same value as YD, LO = Oxffffffff. The actual number of the vertical lines is 500. Data stream for OPTION mode BIH (YD = Oxffffffff, LO = Oxffffffff, VLENGTH =1 - Other parameters shall be set appropriately). Encoded image data of the first stripe (line 1-500). ESC, SDNORM. ESC, NEWL
23、EN (note that this is first marker), New YD (= 500). Encoded data of the second stripe (note that “null” means there is no data). ESC. SDNORM or SDRST. 2 Recommendation T.8Wor.l (02/97) STD-ITU-T RECMN T.85-ENGL 1977 D LIBb2591 Ob335b2 675 D 3) Add Appendix II as follows: Appendix II The bit order o
24、f Coded Data Transmission on communication line conforming to the description of clause 3 “Principle? of this Recommendation Here, the coded data stream example described in 7.1IT.82 and Table 26IT.82 is used as an example. PSCD: 6989 99% 32ea faa0 - The bit order of the coded data at the output of
25、encoder is described as MSB LSB o1 101001 1000 100 1 10011001 01011100 00110010 11101010 69 89 99 5c 32 ea These coded data are transmitted LSB first for each byte, then 100101 10 1001001 10011001 O01 11010 O1001 100 010101 11 is the bit order on communication line. The receiving FAX will reorder th
26、e received bits and treat the coded data as MSB LSB 01101001 10001001 1001 100 1 O101 1100 00110010 11101010 69 89 99 5c 32 ea Then the data is to be decoded according to the algorithm described in Recommendation T.82. Recommendation T.85Cor.l (02/97) 3 STD-ITU-T RECMN T.85-ENGL 1777 = 48b2571 Ob335
27、b3 501 Series A Series B Series C Series D Series E Series F Series G Series H Series I Series J Series K Series L Series M Series N Series O Series P Series Q Series R Series S Series T Series U Series V Series X Series Z ITU-T RECOMMENDATIONS SERIES Organization of the work of the ITU-T Means of e
28、xpression: definitions, symbols, classification General telecommunication statistics General tariff principles Overall network operation, telephone service, service operation and human factors Non-telephone telecommunication services Transmission systems and media, digital systems and networks Audio
29、visual and multimedia systems Integrated services digital network Transmission of television, sound programme and other multimedia signals Protection against interference Construction, installation and protection of cables and other elements of outside plant Maintenance: international transmission s
30、ystems, telephone circuits, telegraphy, facsimile and leased circuits Maintenance: international sound programme and television transmission circuits Specifications of measuring equipment Telephone transmission quality, telephone installations, local line networks Switching and signalling Telegraph transmission Telegraph services terminal equipment Terminals for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communication Programming languages
