公开(公告)号：EP0283715A3

公开(公告)日：1988-12-21

申请号：EP88102345

申请日：1988-02-18

申请人： ANT Nachrichtentechnik GmbH

发明人： Lohscheller, Herbert, Dr. Ing. ,  Franke, Uwe, Dipl.-Ing.

IPC分类号： H04N01/415 ,  H04N01/41

CPC分类号： G06T9/007 ,  H04N1/642 ,  H04N11/044 ,  H04N19/154 ,  H04N19/60

公开(公告)号：EP0202425A3

公开(公告)日：1987-09-16

申请号：EP86103848

申请日：1986-03-21

申请人： International Business Machines Corporation

发明人： Chen, Yi-Hsin (NMN) ,  Mintzer, Frederick Cole ,  Pennington, Keith Samuel

IPC分类号： H04N01/415 ,  G06F15/66

CPC分类号： H04N1/40062 ,  H04N1/4055

摘要： An electronic processing system for reproducing mixed images, ie, original images having areas of continuous tone and areas of text, in such a manner that both areas are of balancedm good quality in the reproduction. The image to be reproduced is (1) divided into non-overlapping 4 x 4 blocks of pixels or picture elements, and, (2) each block is classified as either of TEXT or IMAGE, based on the values of the 16 pixels within it. The classification is improved by (3) eliminating short runs of blocks with the same classification. The pixel values are then adjusted by appropriately (4) thresholding those in the TEXT blocks and, (5) averaging those in the IMAGE blocks. The IMAGE block values are quantized to one of 17 levels using an improved error diffusing process and then mapped onto a 4 x 4 pattern preparatory to (6) merging the binary images for the TEXT and IMAGE areas. Converting to various patterns to suit the output device such as a specific printer, is possible by permitting the conversion of the bits for an IMAGE block from one pattern table to another.

公开(公告)号：EP0199065A3

公开(公告)日：1988-09-07

申请号：EP86103439

申请日：1986-03-14

申请人： International Business Machines Corporation

发明人： Toyokawa, Kazuharu

IPC分类号： H04N01/415 ,  H04N01/419 ,  H04N01/41

CPC分类号： H04N19/93

摘要： @ A coding process for a facsimile transmission system employs block coding and dither matrices of black and white picture elements, wherein each matrix represents a portion of a subject (22). The subject is scanned to provide gray-scale tone-level data, and the data of continuous tone regions of the subject is represented by standardized patterns in matrix form. A run of identical patterns is counted in the scanning direction and a symbol incidating the number of such repetitions is placed in the code in lieu of the succession of code words representing individual ones of the repeating patterns. A second symbol is inserted into the code to indicate a succession of runs of repeating patterns in the same column now positioned in two or more rows. The second symbol is utilized in lieu of a repetition of code words corresponding to each of the repeated patterns. The two symbols provide for two dimensional compression of the length of the message for improved efficiency of transmission of pictorial data between the subject and a display of an image of the subject.

公开(公告)号：EP0149050A3

公开(公告)日：1987-09-23

申请号：EP84113739

申请日：1984-11-14

申请人： International Business Machines Corporation

发明人： Asano, Hideo

IPC分类号： H04N01/415

CPC分类号： H04N1/4135 ,  H04N1/415

摘要： Facsimile transmission system in which the PEL data from the scanner unit (1) is sampled by a sample window (21) which equals the PEL size defined in an AM-PM-VSB transmission system. The positions of white or black PELs enclosed by the sample window is detected. The sample window includes four scanned small size PELs, and sixteen four-bit patterns representing the positions of the white or black PELs in the window are assigned to sixteen amplitude levels for amplitude modulation, respectively. These values are stored in a conversion table (7). For each sampled bit group, its bit pattern is determined, and the related data for controlling the amplitude of the carrier signal are fetched from the conversion table.