Kokusai Denshin Denwa Kabushiki Kaisha

Kokusai Denshin Denwa Co., Ltd.

Nippon Telegraph and Telephone Public Corporation

Yasuhiro Yamazaki

Yasushi Wakahara

Hiroichi Teramura

Yukio Nakagome

Toshiaki Endoh

Seiichi Yamamoto

Toshiaki Endo

Toyomichi Yamada

Naohiko Hattori

Kiyohiro Yuuki

Kazuo Hasuike

Kouzo Nakao

Kazunori Matsuo

Teramura Hiroichi

Kozo Nakao

A facsimile image coding method in which a pattern appearing only once in the input image is encoded by the conventional facsimile coding method which sequentially scans the input image as a graphic element thereon for encoding, and a pattern appearing twice or more is encoded by encoding the positional coorinates and the identification code added at the time of registration in the pattern library as in the case of the pattern matching method. As a result of the above operations of the present invention, a high compression ratio, not only for a printed document but also for handwritten and graphic documents, is obtained.

Facsimile image encoding method

An encoding method for facsimile signal which is characterized by encoding data of a line selected out of the all lines of input facsimile signals in a manner of skipping over a predetermined number of lines according to a predetermined encoding method and by encoding the data of one of the thus skipped-over lines from a basic element of higher picture quality contribution judged with reference made to the data of the lines preceding of and/or subsequent to the encoding line which have already been encoded.

Encoding method for facsimile signal

A graded facsimile image signal coding system is disclosed which is provided with means for distributing a multi-graded facsimile picture signal, represented by 2.sup.n gradation levels, into n bit planes corresponding to n digits; initial encoding means for detecting, from picture elements forming each bit plane, picture elements at intervals of .DELTA.X picture elements on every .DELTA.Y-th line and encoding the detected picture elements; and additional coding means for further coding each one of said encoded picture elements with reference to encoded four picture elements positioned around said one picture element to be coded.

Graded facsimile image signal coding system

A facsimile communication system, in which a coding level of a facsimile signal is determined for each image to be transmitted by a coding algorithm of an encoder in correspondence to an image quality of a receiving image sent from the receiving side of the facsimile signal, so that the above-mentioned each image is encoded in the encoder by the use of the coding level and then transmitted to the receiving side.

Fascimile communication system with desired image quality

A facsimile signal coding system is disclosed, in which initial encoding is performed for detecting, from picture elements forming a facsimile picture signal, picture elements at intervals of .DELTA.X picture elements on every .DELTA.Yth line and encoding the detected picture elements. Encoding of mode 1 is carried out for encoding, by referring to four of the encoded picture elements, a picture element surrounded by the reference picture elements and lying centrally thereof. Encoding of mode 2 is performed by encoding, by referring to four picture elements encoded by the initial encoding and the encoding of mode 1, a picture element surrounded by the four picture elements lying above and below it and on its left and right. The initial encoding and the encoding of mode 1 and mode 2 are effected using 2.sup.n (where n is an integer) as an initial value of each of the .DELTA.X and .DELTA.Y and thereafter the encoding operations of mode 1 and mode 2 are repeated with the values of the .DELTA.X and .DELTA.Y reduced by half.

Quality selectable facsimile image coding system

A coding method for a multilevel-gradated picture signal is disclosed, in that a series of binary codes obtained by processing a multilevel-gradated original picture signal for binary representation are segmented every predetermined number n of picture elements on each scanning line to form blocks, respectively capable of assuming value '0' to '2n-1'; and the value of a block having changed its value and its position on the scanning line are encoded so as to be reproduced on the reproducing side.

Coding method for multilevel-gradated picture signal

A dot-type printer has heretofore been unable to output characters of the pitch which does not coincide with multiples of the dot-width by integers when such dot-width is either electrically or mechanically fixed, causing considerable errors and not being in compliance with the recommendation of CCITT. The system according to the present invention provides a means to obtain the distance between a character and a printing reference point and to output the character at a position which is separated from the reference point by the distance in a multiple of the dot-width by an integer and which is either immediately before or after the point of the distance thus obtained. By such output control, the character outputted can remain within the range recommended by CCITT with only negligible errors.

Output control system for dot-type printer

In a digitalized facsimile transmission system, (k) number of scanning lines (k=2 or 4) are encoded to a relative address code and the next scanning line is encoded to a run length code, and each scanning line has the related synchronization code pattern corresponding either said relative address code or said run length code. Thus, the effect of a transmission error is restricted within one scanning line when that error occurs in the scanning line encoded to run length code, or k lines when that error occurs in the scanning line encoded to relative address code. The value (k) is switched between k=2 and k=4 according to the instantaneous quality of a communication line. When the quality is good, k=4 is selected, and when the quality is bad, k=2 is selected. The reception side can switch the decoding systems between relative address decode and run length decode, by being controlled through the related synchronization code patterns. A synchronization code pattern has a plurality of O's inserted between a pair of 1's (1000 . . . 0001), and the number of O's between said 1's indicates one of relative address code and run length code. In order to discriminate a facsimile information from a synchronization code pattern, when the facsimile information has the more continuous O's than (n), an idle signal having the value '1' is inserted in every (n-1) number of continuous O's of the facsimile information. Said idle signal is deleted automatically in the receiver.

Digital signal control system in a facsimile communication

A coding method for a two-level facsimile signal by the use of the two-dimensional coding principle, in which when successively coding addresses of a facsimile signal representative of the positions of information change picture elements, each having a binary level different from that of an immediately preceding picutre element, the above-mentioned addresses on each coding scanning line are classified into three modes that are determined by the states of information change picture elements on the coding scanning line and on a reference scanning line immediately preceding the coding scanning line. The above two-dimensinal coding principle and a one-dimensional coding principle may be adaptively adopted to shorten the transmission time and to lessen the influence of a transmission error.

Coding method for facsimile signal

A coding method for facsimile signals in which a binary facsimile signal is divided into fundamental picture elements sampled every N picture elements and elemental picture elements lying between adjacent ones of the fundamental picture elements. The fundamental picture elements are sequentially encoded for each succession, whereas the elemental picture elements are encoded only at required ones to effectively reduce the transmission time.

A transmission method for a facsimile signal by the use of the two-dimensional coding principle, in which when successively coding addresses of a facsimile signal representative of the positions of information change picture elements, each having a binary value different from that of an immediately preceding picture element, the above-mentioned addresses on each coding scanning line are classified into three modes that are determined by the states of information change picture elements on the coding scanning line and on a reference scanning line immediately preceding the coding scanning line. The above two-dimensional coding principle and a one-dimensional coding principle may be adaptively adopted to shorten the transmission time and to lessen the influence of a transmission error.

Transmission method and system for facsimile signal

A facsimile signal coding system, in which a facsimile signal is divided into a plurality of scanning line groups each including a predetermined number of scanning lines. A substantially central one of the scanning lines of each group is encoded by a coding method without referring to information of a scanning line adjacent to the central scanning line. Information of the remaining lines above the central scanning line is sequentially encoded upwardly from the central scanning line using information of the just precedently encoded line as reference information. Information of the remaining lines below the central scanning line is sequentially encoded downwardly from the central scanning line using information of the just precedently encoded line as reference information.

Facsimile signal coding system

A method for coding addresses of information change picture elements each having information different from that of the immediately preceding picture element in a facsimile signal obtained by successively scanning an original picture, in which the information change picture elements are classified into deviation change points each having a high correlation to a final reference change point selected from coded information change picture elements, and new change points each having substantially no correlation to the final reference change point. The deviation change points are coded to indicate the direction and length of each deviation thereof from the corresponding final reference change point. The new change points are coded to indicate each distance thereto from the immediately preceding information change picture element.

Method for coding addresses of information change picture elements in

A facsimile signal converter for converting an input facsimile signal into an output facsimile signal having a scanning line density different from that of the input facsimile signal. A table circuit is provided for developing white and black states of each output picture element of the output facsimile signal in correspondence to a predetermined number of combinations of states of reference picture elements and the geometric relation between the reference picture elements and the output picture elements. The reference picture element corresponds to at least one input picture element of the input facsimile signal adjacent to each output picture element of the output facsimile signal in consideration of a state of superimposing an input pattern on an output pattern indicated respectively by the input facsimile signal and the output facsimile signal. The white and black states of the output picture elements are read out from the table circuit to provide the output facsimile signal in response to each input picture element of the input facsimile signal on the base of the instant conditions of the geometric relation and the reference picture elements.

Facsimile signal converter

A method for interline-coding a facsimile signal, in which information of scanning lines of the input facsimile signal is alternately divided into information of at least one first unit line and information of at least one second unit line. A first one of the first unit lines is first coded in accordance with a predetermined coding principle. The information of the next one of the first unit lines is secondly coded in accordance with a predetermined coding principle prior to coding of information of the first one of said second unit lines. The information of the first one of the second unit lines is thirdly coded by two-dimensional predictive coding using, as reference information, the information of the first one and the next one of the first unit lines. The operations of the second coding and the operation of the third coding are repeatedly achieved thereafter.

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Hiratsuka, Japan

Yasuhiro Yamazaki