公开(公告)号：CA1335309C

公开(公告)日：1995-04-18

申请号：CA471574

申请日：1985-01-04

Applicant: IBM

Inventor： ANDERSON KAREN L ,  GOERTZEL GERALD ,  MITCHELL JOAN L

IPC: G06T9/00 ,  H04N1/417

Abstract: A method for encoding and decoding digital image data, includes the steps of testing the data for a vertical relationship between adjacent lines of the image, generating directly a reference code word representative of the vertical relationship for each successful test, generating by table lookup a run code word for a stream of data bits of common value for each unsuccessful test, wherein a data element representing a number of bits in a code word is stored at a predetermined offset from a table entry for the code word, merging the vertical reference code words and the run code words generated by the above steps to form an encoded data stream, testing an encoded data stream for a reference code, decoding directly the vertical relationship from the reference code for each successful test; decoding by table lookup a run of bits of common value by serial examination of said encoded data stream for each unsuccessful test and storing data decoded by the above steps in a predetermined relationship.

公开(公告)号：DE3688517D1

公开(公告)日：1993-07-08

申请号：DE3688517

申请日：1986-03-07

Applicant: IBM

Inventor： GOERTZEL GERALD

IPC: G06F5/00 ,  H03M7/40 ,  H03M7/42 ,  G06F15/40

公开(公告)号：DE3582701D1

公开(公告)日：1991-06-06

申请号：DE3582701

申请日：1985-06-11

Applicant: IBM

Inventor： ANDERSON KAREN LOUISE ,  MITCHELL JOAN LA VERNE ,  PENNEBAKER WILLIAM BOONE ,  GOERTZEL GERALD

IPC: G06F3/153 ,  G06T9/00 ,  H03M7/46 ,  H04N1/41 ,  H04N1/419

Abstract: A method for converting an image from a bit map to a run end or run length representation includes the steps of : storing the image as a bit map representation; accessing for each byte in an image by a look-up table a selected routine, corresponding to such byte, from a number of routines for converting bit strings to run representations, wherein the look-up table accessed is selected in accordance with a color value of a preceding pixel binary bit; and executing the selected routine on the current byte to convert the bit string to a run representation; storing in a run representation buffer, as a count value, each run representation; repeating the above steps of accessing and executing for each byte and storing for each run of continuous color to the end of the image.

公开(公告)号：DE3581221D1

公开(公告)日：1991-02-14

申请号：DE3581221

申请日：1985-02-22

Applicant: IBM

Inventor： GOERTZEL GERALD ,  MITCHELL JOAN LA VERNE

IPC: H03M7/40 ,  H03M7/42

Abstract: Data compression for transfer (storage or communication) by a continuously adaptive probability decision model, closely approaches the compression entropy limit. Sender and receiver perform symmetrical compression/decompression of binary decision n according to probabilities calculated independently from the transfer sequence of 1...n-1 binary decisions. Sender and receiver dynamically adapt the model probabilities, as a cumulative function of previously presented decisions, for optimal compression/decompression.Adaptive models for sender and receiver are symmetrical, to preserve data identity; transfer optimization is the intent. The source model includes a state generator and an adaptive probability generator, which dynamically modify the coding of decisions according to state, probability and bit signals, and adapt for the next decision. The system calculates probability history for all decisions, including the current decision, but uses probability history for decision n-1 (the penultimately current decision) for encoding decision n (the dynamically current decision). The system, separately at source and destination, reconfigures the compression/expansion algorithm, on a penultimately current basis, codes each decision in the data stream optimally, according to its own character in relation to the calculated probability history, and dynamically reconfigures the current decision to the penultimately current transfer optimum.

公开(公告)号：CA1248878A

公开(公告)日：1989-01-17

申请号：CA502705

申请日：1986-02-25

Applicant: IBM

Inventor： GOERTZEL GERALD ,  THOMPSON GERHARD R

IPC: G06F3/12 ,  B41J2/52 ,  G06K15/10 ,  H04N1/40 ,  H04N1/405 ,  H04N1/00

Abstract: A system for producing improved halftone images from continuous tone input images, the pixels of which have been digitized as gray scale values, using a printer having the capability to print a set of output pel patterns producing a respective set of discrete gray scale values, is disclosed. Blocks of pel patterns with discrete gray scale values approximating the gray scale values of the input pixels are selected for printing, and the error in a first block due to the difference between the gray scale value associated with the block and the gray scale value of the corresponding input pixel, is determined. To diffuse this error it is distributed to at least two adjacent blocks using a random number generator to determine the distribution such that a random fraction of said error is distributed to one block and the remainder is distributed to the other block. This error diffusion process is carried through the adjacent blocks taking into account the error fraction already assigned. For edge enhancement the brightness gradient surrounding each input pixel is determined and a threshold value is set below which said gradient is classified as small and above which it is classified as large. When said gradient is small, the selected discrete pattern is printed for the pixel, and when said gradient is large, the pel pattern is altered and the block representing the pixel is printed biasing the pels therein toward the darker input pixels.

公开(公告)号：AU536299B2

公开(公告)日：1984-05-03

申请号：AU6497580

申请日：1980-12-02

Applicant: IBM

Inventor： GOERTZEL GERALD ,  POWELL CARL GEORGE ,  TSENG SAMUEL CHIN-CHONG

IPC: G09G5/28 ,  B41B19/01 ,  G06K15/10 ,  G06T11/20 ,  G09G5/24 ,  G06K9/00 ,  G06K9/46

Abstract: A character compaction and generation method and apparatus which is particularly adapted to the generation of complex characters such as Kanji characters. A dot matrix (Fig. 2-1) defining a given character is compacted into a sparse matrix (Fig. 2-7), with the original character being reconstructed for printing or display from the compacted character defined in the sparse matrix. Each character in the complex character set is compacted and stored in memory (50) one time only, with decompaction being performed each time a given character is to be generated. A set of symbols are defined to represent different patterns which occur frequently in the entire complex character set. Different combinations of the symbols define a given character. The information stored for each sparse matrix representing a given character is comprised of eacn symbol in the sparse matrix, its position, and its size parameter if the symbol represents a family of patterns which differ only in size. Three groups (A, B, C,) of different patterns are defined which occur frequently in the complex character set, namely, a first group (A) which has a fixed size for each pattern, a second group (B) which has one size parameter which must be specified for each pattern, and a third group (Cl which has a plurality of size parameters which must be specified for each pattern. Certain ones of the characters have elements of different patterns which overlap, such that the character may be encoded utilizing less symbols, and according less bytes of data. A given pattern may be generated atthe same time another pattern is being decoded.