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1、m a m Y- Bandwidth compression. A technique to reduce the band- width needed to transmit a given amount of facsimile information in a given time or to reduce the time needed to transmit a given amount of facsimile information in a given bandwidth. Baud. The number of changes in signai state per seco
2、nd in a digital signal sent by a modem. A baud may contain four or more bits as in a CCIT V.29 modem. Bit. The contraction for binary digit, the smallest amount Color facsimile system. A facsimile system which produces the recorded copy in more than one color. Typically, a full color image is produc
3、ed by sending images for three primary colors. Compatibility. Matching facsimile transmitter and facsimile receiver characteristics which permits acceptable facsimile copy to be received. Compression ratio. In digital facsimile, the ratio of the total bits used to represent the original to the total
4、 number of en- coded bits. Continuous tone image (analog gray scale image). An image in which each resolvable element may be represented by one of a continuous range of tones. Contouring. Density step lines in recorded copy resulting from quantization of an original image which has observable gray s
5、hadings between adjacent quantization intervals. Digital facsimile. That form of facsimile in which densities of the original are sampled and quantized as a digital signal for processing, transmission, or storage. Direct recording. That type of facsimile in which a visible recorded copy is produced
6、without subsequent processing. Document. A set of one or more pages which can be transmitted as a unit. Electrolytic recording. Recording with signal-controlled cur- rent through an electrolyte in the recording paper, depositing metallic ions to produce a mark. Electronic shading. An electronic meth
7、od of compensating for variations in sensitivity of individual sensors of a sensor array or variation in illumination of copy being scanned. This may be done by correcting the analog signai from each sen- sor sample under control of stored digital information. Electrosensitive recording. Recording w
8、ith an electrical signal which passes directly into the record medium. Electrostatic recording. Recording by means of a signai con- trolled electrostatic field. NOTE: A toner i s required to make the image visible. 1 Copyright AIIM International Provided by IHS under license with AIIM Licensee=IHS E
9、mployees/1111111001, User=Wing, Bernie Not for Resale, 04/18/2007 05:29:07 MDTNo reproduction or networking permitted without license from IHS -,-,- A I I M TRI7 89 IOL23qB 0000b7b 2 End-of-line (EOL). In Group 3 digital facsimile systems, a sequence of digital symbols introduced at the end of a sca
10、n- ning line to establish synchronization of decoding and for error detection. Facsuiiile. The process by which a document i s scanned, con- verted into the electrical signals, transmitted, and recorded or displayed as a copy of the original. F a d e copy. A recorded copy of an original produced by
11、a facsimile recorder. Facsimile receiver. The apparatus employed to translate pic- ture signals from the communications channel into a fac- simile copy of the original. Facsimile recorder. That part of the facsimile receiver which performs the final conversion of electrical picture signals to an ima
12、ge of the original on the record medium. Facsimile signal. See picture signal. Facsimile transmitter. The apparatus used to translate the original into picture signals suitable for delivery to the com- munication system. Fax. An abbreviation for facsimile. Fingerprint facsimile. Facsimile equipment
13、used to transmit fingerprint cards. N o m Existing systems send 8 inch x 8 inch cards at 192 lines per inch. Ghost. In analog facsimile, a spurious image resulting from echo, envelope delay distortion, or multipath reception. Group 1. Analog facsimile equipment per CCIIT Recom- mendation T.2. (Sends
14、 an A4 or 8.5 x 11 inch page in six minutes over a voice grade telephone line using frequency modulation with 1,300 hertz corresponding white and 2,100 hertz to black of the original.) Note: Since North American six minute equipments use 1,500 hertz white and 2,400 hertz black, they are not compatib
15、le with Group 1 equipments. Group 2. Analog facsimile equipment per CCITT Recom- mendation T.3. (Sends an A4 or 8.5 x 11 inch page in three minutes over a voice grade telephone line using 2,100 hertz Ah4-PM-VSB.) Group 3. Digital facsimile equipment per CCIIT Recom- mendation T.4. (Sends an A4 or 8.
16、5 x 11 inch page typical- ly in a half minute over a voice grade telephone line,) Group 4. Digital facsimile equipment per CCITT Recom- mendations T.5 and T.6. (Uses public data networks and their procedures for essentially error-free reception. May also be used on the public switched telephone netw
17、ork with an appropriate modulation process.) Halftone image. An image that has been converted from a continuous tone image into a two tone image while retain- ing the appearance of a continuous tone image. Handshaking. An exchange of signals (calied control pro- cedures) between the facsimile transm
18、itter and facsimile receiver to verify that facsimile transmission can proceed, to determine which specifications wiU be used and to verify reception of the documents sent. Horizontal resolution. The number of picture elements per inch (or mm) in the direction of scanning or recording. Jitter (in fa
19、csimile). Irregular error in the position of the recorded spot along the recorded line. NOTE: This i s noticeable on the recording of a vertical line. K factor (in modified read coding for Group 3 facsimile). The number of facsimile scanning lines i n a set used for coding. At the most, K minus 1 li
20、nes are coded two- dimensionally to iimit the disturbed area in the event of transmission errors. In CCITT Group 3, K=2 for 3.85 lines/mm and K=4 for 7.7 lines/mm. In Group 4, K = infinity. Lines Per Inch (or mm). The number of scanning or record- ing lines per unit length measured perpendicular to
21、the direc- tion of scanning. Line-fo-line correlation. The correlation of image informa- tion from scanning line to scanning line. Useful for two- dimensional coding, e.g. modified read. Maximum keying frequency. The frequency equal to one- half the nhmber of picture elements per second. Mobile facs
22、imile. Facsimile equipment used within vehicles for facsimile. Modified Huffman (MH) coding. A one-dimensional run length digital scheme of coding white and black runs where the shortest length code words represent the most probable run lengths. Used by Group 3 facsimile. Modified read (MR) coding.
23、A two-dimensional optional digital coding scheme for Group 3 facsimile. NOTE: MR provides an improved transmission speed over modified Huffman coding. Newsphoto facsimile. Facsimile equipment used to transmit photographs for newspaper or magazine publishing. Original. A page which is transmitted by
24、facsimile. Pel. A picture element that contains only black-white infor- mation (no gray shading). See pixel. Photographic recording. Recording by the exposure of a photosensitive surface to a signaiantrolid light beam or spot. 2 Copyright AIIM International Provided by IHS under license with AIIM Li
25、censee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/18/2007 05:29:07 MDTNo reproduction or networking permitted without license from IHS -,-,- AIIM TR17 89 W 1012348 0000677 4 W Picture element. The smallest area of the original which is sampled and represented by an electrical sig
26、nal. See pel and pixel. Picture signal. A signal resulting from the scanning process or an electronically generated equivalent. Pixel. A picture element that has more than two levels of gray scale information. See pel. Pixel interpolation. Generation of additional unscanned pixels by logical compari
27、son of nearby scanned pixels to simulate increased resolution. Interpolation may be one or two dimensional. Quantizing levels. In a digital facsimile system the number of different gray steps representing a continuous tone image. See contouring. Record medium. The physical medium on which the fac- s
28、imile recorder forms an image of the original. Record sheet. The medium used to produce the recorded copy. The record medium and the record sheet may be identical. Recorded copy. A hard copy of the original produced by facsimile. Recording. The process of converting the picture signal in a facsimile
29、 receiver to an image on the record medium. Recording spot. The image area corresponding to a picture element formed at the record medium by the, facsimile recorder. Redundancy reduction. Coding for elimination of redundant information in the picture signal to reduce the amount of information needed
30、 for transmission or storage. NOTE: The amount of redundancy reduction will vary with the information content of the original. See compression ratio. Resolution. A measure of capability to delineate picture detail. Scanner. That part of the facsimile transmitter which systematically translates the d
31、ensities of the original into a signal-wave form. Scanning. The process of analyzing successively the densities of the original according to a predetermined pattern. Scanning direction, Normal direction is from left to right and top to bottom of the original as when reading a page of print. Scanning
32、 line length. See total line length. Scanning spot. The area on the original viewed instantane- ously by the photosensor of the scanner. Skew. 1. The deviation of the recorded copy from rectan- gularity due to asynchronism between scanner and recorder. 2. Angular misalignment of the original from th
33、e paper feed direction. 3. Deviation of the angle of the scanning line or recording line from a perpendicular to the paper path. S o f t copy. That form of facsimile which displays the received image on a cathode ray tube or similar display. Subject copy. See original. Synchronizing. The maintenance
34、 of the proper position of the recording spot while it is writing to produce an undis- torted recorded copy of the original. Themai recording. That type of recording which is produced principally by signal-controlled thermal action. NOTE: Direct thermal recording involves direct imaghg on the record
35、 medium. Thermal transfer recording involves heat from a thermal print head transferring marking from a c a r - bon ribbon or overlay sheet to another sheet, forming the recorded copy. Some recorders produce full color recordings by successively overwriting different colors in the same area. Totai l
36、ine length VLL). In digital facsimile, the F L is equal to the pels per scan line divided by the pels per mm. Transmission time. The time for sending a single page (elapsed time between the start of picture signals and the detection of end-of-message signal by the facsimile receiver). Xerographic re
37、cording. Recording by action of a light spot on an electrically charged photo-conductive insulating sur- face where the latent image is subsequently developed with a toner. 1.3 CCIT Standards for Office Facsimile Standards for office type fax started in October 1966 with RS-328, generated by Committ
38、ee TR-29 on Facsimile Equip- ment and Systems of the Electronics Industry Association I A ) . This standard is obsolete and TR-29 now represents the U.S. through the State Department in CCIT (Interna- tional Telegraph and Telephone Consultative Committee) activities on facsimile. The CCITT completed
39、 standards for Group 1 fax in 1968, Group 2 i n 1976, Group 3 in 1980, and Group 4 in 1984. These standards are updated every four years after issuance to correspond with the four year CCITT cycle. The CCITT, part of the International Telecommunica- tions Union of the United Nations, developed the f
40、ollowing recommendations, effectively standards, for office-type fac- simile units (see Table 1). 3 Copyright AIIM International Provided by IHS under license with AIIM Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/18/2007 05:29:07 MDTNo reproduction or networking permitted
41、 without license from IHS -,-,- AIIM T R I 7 89 W Loi12348 OOOOb78 b W ;roup 1 2 3 1,2,3 - 4 4 4 4 4 4 4 4 4 4 4 4 4 Recommendation T.2 T.3 T.4 T.30 Standardization of Group 1 Facsimile Apparatus for Document Transmission Standardization of Group 2 Facsimile Apparatus for Document Transmission Stand
42、ardization of Group 3 Facsimile Apparatus for Document Transmission Procedures for Document Facsimile Transmissions for the General Switched Telephone Network NOTE: The general switched telephone network is usualy referred to as the public switched telephone network o. It is the regular telephone ne
43、twork, once called DDD. T.563 Terminal Characteristics for Group 4 Facsimile Apparatus T.503 Document Application Profile for Interchange of G4 Documents T.521 Communication Profile for BTO Bulk Document Transfer Under T.62 Session Service Environment T.6 Facsimile Coding Schemes and Coding Control
44、Functions for Group 4 Facsimile Apparatus T.62 Control Procedures for Teletex and Group 4 Facsimile Services T.70 Network Independent Basic Transport Services for the Telematic Services T.72 Terminal Capabilities for Mixed Mode Operation E.5 is replaced by these T . 5 0 0 series recommendations m.73
45、 w a s replaced by the foiowing T.400 Series-Recommendations for Document Transfer, Access, and Manipulation TAM), Office Document Architecture (ODA), and Interchange Format T.411 Introduction American Libraries, January, 1988, pg. 60. 13 Copyright AIIM International Provided by IHS under license wi
46、th AIIM Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/18/2007 05:29:07 MDTNo reproduction or networking permitted without license from IHS -,-,- I AIIM T R I 7 89 LO12348 0000b88 9 Table 3. Features of Group 3 Fax Machines PRICE CLASS 12345 n f s m m aaaaa nfmaa nfmaa aaaaa
47、 fmaaa maaaa f m m m m n f f m m nnff* nfmaa fmaaa FEATURE Alternate number calling. The document may be sent to an alternate fax machine if the fax machine originally called is in use. Automatic background control (ABC). When sending a page, the same results are obtained for gray or colored backgro
48、unds as for white. The ABC circuit adjusts the background signal level to be the same as white before digitizing it to black/white. This saves the operator from trying to guess the proper setting: Automatic cutter. This very desirable feature cuts the received pages and stacks them in the receive tr
49、ay. Without a cutter, a long banner of paper spills on the floor if documents are received while the fax machine is unattended. The time saved can easily pay for the extra cost. If, however, the fax pageis torn off for immediate use as received, a cutter is probably not needed. Automatic dialing. The phone numbers of fax machines frequently called can be stored in memory and used for sending fax transmis