1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TERMINAL EQUIPMENT AND PROTOCOLS FOR TELEMATIC SERVICES T .22 (03/93) STANDARDIZED TEST CHARTS FOR DOCUMENT FACSIMILE TRANSMISSIONS ITU-T Recommendation T.22 (Previously “CCITT Recommendation“) ITU-T RECMN*T.
2、ZZ! 73 4862573 0583742 270 FOREWORD The IT Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecom- munication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standard
3、izing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. ITU-T Recommendation T.22 was prepared
4、 by the IT-T Study Group VI11 (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). NOTES 1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standard
5、ization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCJR and the IFRI3 have been replaced by the Radiocommunication Sector. 2 telecommunication administration and a recognized operating agency. In this Recommendation, the expression “Administration” is used
6、for conciseness to indicate both a O ITU 1994 I All rights reserved. No part of this publication 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. Recommendation T.22 STANDARDIZED TES
7、T CHARTS FOR DOCUMENT FACSIMILE TRANSMISSIONS (Helsinki, 1993) The -T, considering (a) that a standardized test chart to check the quality of document facsimile transmissions will have great advantages. The advancing technology of document facsimile has brought forth monochrome testing requirements
8、that cannot be adequately met with current test charts. New higher resolution needs and transmission of high quality continuous tone gray scale must be taken into consideration; (b) definition of two new test charts: that conflicting test chart reproduction requirements for black-white patterns and
9、continous tone has led to the - one, high contrast “facsimile test chart” for evaluating the technical quality of the page and the legibility of the text; - the other, “continuous tone addendum” for the evaluation of the technical quality of continous tone information, unanimously adopts the view (1
10、) T-T standardized test charts; that tests of document facsimile transmission quality should be carried out in the international service using the (2) for sale by the . There are two types of charts: that these test charts should be produced by the ITU under the supervision of the -T and should be o
11、ffered - - Test chart No. 4: “Facsimile test chart” intended for the general evaluation of technical quality; Test chart No. 5: “Continuous tone addendum” intended to check tonal quality. The charts are described in Annex A; the specimens printed in Annex A cannot be used for measurements; (3) facil
12、ities, and facsimile apparatus in accordance with appropriate T-Series Recommendations. that the charts should be used with electronic document storage facilities, electronic document transmission Annex A Description of the standardized document facsimile test charts (This annex forms an integral pa
13、rt of this Recommendation) A.l Dimensions of the test charts Test chart No. 4 Test chart No. 5 - length: 302 mm 279 mm - width: 222 mm 216 mm Recommendation T.22 (03/93) 1 I ITU-T RECMN*T*22 73 W Y862591 0583744 Ob3 W They are divided into sections numbered: - - 1-17 on test chart No. 4 for resoluti
14、on testing, 1-6 on test chart No. 5 for tonal quality testing. A test-chart section number is also the last part of a subclause number denoting the subclause, in A.2 and A.3 below, which describe in detail the given section of the test chart. A.2 Test chart No. 4 - Black-white facsimile test chart B
15、WO1 This monochrome test chart has black-white patterns, text and line work printed on high gamma photographic paper for optimum sharpness and high contrast without fogging the white areas next to black markings. The overall size of the printed chart is 222 x 302 mm (8 3/4 x 11 7/8 inches) to allow
16、for maximum paper size tolerances. Pattern descriptions The overall size of the printed chart is 222 x 302 mm. The patterns that make up the chart are defined below. Refer to the corresponding numbers on the test chart 4 pattern arrangement. A.2.1 Pattern 1 - ITU-T border of 4 scales (between arrowh
17、eads) with inch and millimeter markings The 5 and 10 mm lines are extended. The arrows near the ends (and pointing vertically downwards) are 8 112 inches apart and centered on the page. A.2.2 Pattern 2 - Black bar across full page width, and a scale in inches across the top and along the left side M
18、arkings start from O in the middle of the page with 0.1 inch scale. The vertical border at the left side of the chart is marked in inches. A.2.3 Pattern 3 - Four patterns of truncated fan-type multiple-line pattern with low taper rate The larger patterns are calibrated in black plus white lines per
19、inch, and the smaller ones are calibrated in microns. A.2.4 Pattern 4 - Gurley type Pestrecov star pattern with circles of 50,100 and 200 lines per 25.4 mm This pattern is better for detecting some moire phenomena than pattern 3. A.2.5 Pattern 5 - Alternating black and white lines Upper pattern is 1
20、50 lines per 25.4 mm, inclined at 3 degrees from vertical. The lower pattern is 200 lines per 25.4 mm, inclined at 2 degrees from vertical. The angle is to allow the lines to drift through a match and a mismatch with the photosensor array elements. A.2.6 Bar Patterns of 100,150,200,300,400 and 600 l
21、ines per 25.4 mm. Pattern 6 - Black-white bar patterns A.2.7 Pattern 7 - Isolated black and white lines The vertical pattern is inclined at 5 degrees from vertical. A.2.8 Pattern 8 - NIST type resolution pattern Calibrated in line pairs (black plus white) per millimeter with the smallest patterns ne
22、ar the center of the chart. A.2.9 Pattern 9 - Tapered isolated black and white line patterns with the line width calibrated in microns or inches Recommendation T.22 (03/93) I 2 ITU-T RECMN*T=ZZ 93 4862593 0583745 TTT = A.2.10 Pattern 10 - Black-white bar pattern of 5 black plus white bars per 25.4 m
23、m A.2.11 Pattern 11 - Parallel lines inclined at 5 degrees from vertical A.2.12 Pattern 12 - NET type resolution pattern Calibrated in line pairs (black plus white) per millimeter with the smallest patterns near the edge of the chart. A.2.13 Pattern 13 - Diagonal line for checking irregularities in
24、vertical pitch Received lines with errors will show breaks or steps in this line. A.2.14 Pattern 14 - IS0 character hexagonal lie patterns for readability testing A.2.15 The 65 and 120 are the number of dots per 25.4 mm measured at a 45 degree angle. Pattern 15 - Halftone dot screens of 10,50 and 90
25、 percent black A.2.16 Pattern 16 - Line crossing pattern The center to center line separation is 0.15 inches on the left end and 0.05 inches on the right end. The number of scanning line crossings of both lines multiplied by 10 is the vertical line pitch in lines per 25.4 mm. A.2.17 Pattern 17 - Tex
26、t in English, Arabic, Chinese, Russian, Spanish and French. Engiish text is in 12,10,8, 6,4 and 2 point sizes A.3 Test Chart No. 5 - Continuous tone facsimile test chart CTO1 This continuous tone test chart is printed on low gamma photographic material that preserves the complete gray scale between
27、paper white and black for continuous tone photographs. It can be used for testing both facsimile machines with gray scale capability and those machines that are black-white only. The black-white threshold setting of the facsimile scanner can be set very accurately with this chart. Pattern descriptio
28、ns The overall size of the printed chart is 279 x 216 mm. The patterns that make up the chart are defined below. Refer to the corresponding numbers on the test chart 5 pattern arrangement. A.3.1 From black on the left to white on the right. Pattern 1 - A continuous (stepless) density wedge A.3.2 Whi
29、te on the left. Pattern 2 - A reverse of the continuous wedge of Pattern 1 A.3.3 Pattern 3 - A 48-step density tablet With 3 rows of 16 density steps from white to black. Steps are designed for equal-perceptibility human observers (see Table A. 1). A.3.4 From black to white (see Table A.2). Pattern
30、4 - A set of 16 horizontai gray scale strips Recommendation T.22 (0-3) 3 ITU-T RECMN*T=22 93 4862593 0.583746 936 TABLE A.lR.22 Pattern 3 density values 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 strip A 0.00 0.02 0.03 0.04 0.06 0.09 o. 10 0.12 0.12 0.14 0.15 0.17 O. 19 0.21 0.23 0.24 B O. 29 0.33 0.37
31、0.38 0.39 0.43 0.45 0.50 0.54 0.56 0.60 0.62 0.66 0.68 0.69 0.73 TABLE A.2.22 Pattern 4 density values Density 1.937 1.812 1.687 1.562 1.437 1.312 1.187 1.062 strip 9 10 11 12 13 14 15 16 A.3.5 A.3.6 Pattern 6 - Portrait Pattern 5 - An architecturai photo showing fine detail C 0.85 0.90 0.93 0.97 1
32、.o1 1 .O6 1.10 1.16 1.20 1.27 1.31 1.33 1.41 1 .so 1.60 1.71 Density 0.937 0.812 0.687 0.562 0.437 0.313 0.187 0.062 4 Recommendation T.22 (03/93) ITU-T RECMN*T=22 93 4862593 0583747 872 = Test chart 4 - Pattern arrangemeat 2 6 Recommendation T.22 (03193) ITU-T RECMN*T.ZZ! 93 4862593 0583748 709 = 1
33、111111) 120 11111 ABCDEFGHIJKLMNOPQRSTUWXYZ - II abcde f ghi j klmnopqrstuvwxy z ,90.,vn,w 1234567890 Courier 12 pt. - Il AECDZFGW-Z -mwn-w ABCDEFGHUKLMNOPORSNVWXYZ abcdefghmmpqistwnnwry2 123434587890 HelWca Madlum 8 pt ABCDEFCHIJKLMNOPQRSTWwxz abcdelghiJklmnopqrsluvwxyr 1234567890 Helvelica Medium
34、i0 ot. ABCDEFGHIJKLMHOPQRSTUVUXYZ abcdefghijklmnopqrstuvwxye 12345 67890 Prestige Elite old sbcdefghljklmnopqrstuvwxyr 1234567890 Italia Book Recommendation T.22 (03/93) 7 ITU-T RECMN*T=22 93 m 4862591 0583749 645 m Test chart 5 - Pattern arrangement 1 2 3 4 5 6 t081 3010-9WdO: 8 Recommendation T.22 (03/93) ITU-T RECMN*T*22 93 4862593 0583750 367 = 1 2 3 45 6 78 9 10 11 12 13 14 15 16 xKI1441 -93/dC4 Continuou tone facsimile test chart CTOl Recommendation T.22 (03/93) 9
