1、 ITU-T RECMN*T=85 95 4862591 Ob02718 738 INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TERMINALS FOR TELEMATIC SERVICES T.85 (08/95) APPLICATION PROFILE FOR RECOMMENDATION T.82 - PROGRESSIVE BI-LEVEL IMAGE COMPRESSION (JBIG CODING SCHEME) FOR FACSIMILE A
2、PPARATUS ITU-T Recommendation T.85 (Previously “CCIlT Recommendation“) ITU-T RECHNbT.85 95 m 48b25911 Ob027119 674 m FOREWORD The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical,
3、 operating and tariff questions and issuing Recommen- dations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, i
4、n their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). IT-T Recommendation T.85 was prepared by ITU-T Study Group 8 (1993-1996) and was approved un
5、der the WTSC Resolution No. 1 procedure on the 1 1th of August 1995. NOTE In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. O ITU 1995 All rights reserved. NO part of this publication
6、 may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. ITU-T RECMN*T*BS 95 m YB62591 Ob02720 39b = CONTENTS 1 Scope 2 References 3 Principle . 4 4.1 Function for facsimile application 4.2
7、 Page boundary 4.3 Parameters in BIH . 4.4 Usage of the COMMENT marker segment Application profile of progressive-compatible sequential coding Application profile of progressive coding Application profile of single-progression sequential coding . 5 6 Recommendation T.85 (OW95) Page 1 1 1 1 2 2 2 2 2
8、 2 1 ITU-T RECMN*T-85 95 m 4862591 Ob02721 222 m SUMMARY This Recommendation specifies an application profile to apply the JBIG coding scheme, defined by Recommendation T.82, for facsimile apparatus. The main specifications in this Recommendation are: Application profile of “single-progressive seque
9、ntial coding” is defined. Other profiles (progressive coding) are for further study. Data format consists of header information and coded information. The parameter ranges in the header are specified. 1) 2) ii Recommendation T.85 (08/95) ITU-T RECMN*T*85 95 486259L Ob02722 Lb9 N Recommendation T.85
10、APPLICATION PROFILE FOR RECOMMENDATION T.82 - PROGRESSIVE BI-LEVEL IMAGE COMPRESSION (DIG CODING SCHEME) FOR FACSIMILE APPARATUS (Geneva, 1995) 1 Scope This Recommendation defines an application profile of Recommendation T.82 “Progressive Bi-level Image Compression (JBIG coding scheme)” for facsimil
11、e apparatus. 2 References The following Recommendations, and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to
12、 revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. - ITU-T Recommendation T.82 (1
13、993), Infonnation technology - Coded representation of picture and audio information - Progressive bi-level image compression. For group 3 facsimile: - ITU-T Recommendation T.4. - ITU-T Recommendation T.30. For group 4 facsimile: - ITU-T Recommendation T.503. - ITU-T Recommendation T.521. - ITU-T Re
14、commendation T.563. 3 Principle This Recommendation specifies an application profile for Recommendation T.82 for facsimile apparatus. Recommendation T.82 defines a method for lossless compression encoding and decoding process of a bi-level image. Recommendation T.82 has three types of coding methods
15、: single-progression, sequential coding, progressive-compatible sequential coding and progressive coding. Application profiles for each coding type are described in clauses 4.5 and 6. The use of error free transmission is mandatory for the coding scheme specified in this Recommendation. The Least Si
16、gnificant Bit (LSB) shall be sent first in data transmission. 4 Application profile of single-progression sequential coding This clause describes an application profile of single-progression sequential coding defined in Recommendation T.82 for facsimile apparatus. Recommendation T.85 (OW95) 1 4.1 Fu
17、nction for facsimile application Image data shall be processed in single-bit precision and single resolution-layer in single-progression sequential coding according to Recommendation T.82 for facsimile application. 4.2 Page boundary Signals of page boundaries are defined in relevant Recommendations:
18、 T.30 for Group 3 and T.521 for Group 4 facsimile. 4.3 Parameters in BIH Parameters in Bi-Level Image Header (BIH) are specified precisely in Recommendation T.82. In facsimile applications, within Bi-Level Image Entity (BE), one BIH table shall be assigned to one facsimile document. Table 1 shows th
19、e profile of parameter setting for facsimile applications. The parameter sizes are defined in 6.2.T.82. The range of parameter values in Table 1 does not indicate the number of bits transmitted in each parameter. 4.4 COMMENT - The interpretation of the information transmitted by COMMENT marker segme
20、nt depends on the implementation of both ends. Usage of the COMMENT marker segment 5 For further study. Application profile of progressive-compatible sequential coding 6 For further study. Application profile of progressive coding 2 Recommendation T.85 (08/95) TABLE 1R.85 Parameter DL initial layer
21、to be transmitted Value O fixed D number of differential layers P number of bit planes O fixed 1 fixed lines per stripe at the lowest resolution horizontal image size at layer D XD YD vertical image size at layer D BASIC: 128 OPTION from 1 to YD - Full range of T.82 MX MY maximum horizontal offset a
22、llowed for AT pixel maximum vertical offset allowed for AT pixel From O to 127 O fixed ILEAVE interleaved transmission order of multiple bit plane I Ofixed HITOLO SEQ transmission order of differential layers indication of progressive-compatible sequential coding O fixed O fixed SMID transmission or
23、der of stripes LRLTWO number of reference lines O fixed o/ 1 DPPRIV use of private DP table VLENGTH indication of possible use of NEWLEN marker segment TPDON use of TP for Typical Prediction for differential layers I ofixed 011 O fixed TPBON use of TP for base layer DPON use of Deterministic Predict
24、ion Notes o/ 1 O fixed (See Note 2) DPLAST use of last DP table (See Note 4) O fixed (See Note 1) (See Note 1) (See Note 1) (See Note 1) O: 3 lines 1: 2 lines O: NEWLEN not used 1: NEWLEN may be used (See Note 3) (See Note 1) o OFF 1: ON (See Note i) (See Note 1) (See Note 1) 1 parameters. It is not
25、 necessary to recognize these parameters at receiver. 2 clause 3.563 for Group 4 facsimile. 3 See for 6.2.6.2.82. 4 These parameters are not applied in single-progression sequential coding. Transmitter shall set “O” to these unused Parameter XD, horizontal image size, shall conform to the values defined in clause m.4 for Group 3 facsimile and When using this Recommendation, BASIC is 128. OPTIONS shall be negotiated by the appropriate facsimile protocol. Recommendation T.85 (OW95) 3
