公开(公告)号：DE2801988A1

公开(公告)日：1978-09-07

申请号：DE2801988

申请日：1978-01-18

Applicant: IBM

Inventor： LANGDON GLEN GEORGE ,  RISSANEN JORMA JOHANNEN

IPC: H03M7/40 ,  H03K13/00

Abstract: There is disclosed a method and means for compacting (encoding) and decompacting (decoding) binary bit strings which avoids the blocking of string elements required by Huffman coding and the ever increasing memory as is the case in simple enumerative coding. The method and means arithmetically encodes successive terms or symbols in a symbol string s=ai aj . . . , in which each new term ak in a source alphabet of N symbols gives rise to a new encoded string C(sak) and a new length indicator L(sak). The method and means comprises the steps of forming L(sak) from the recursion L(sak)=L(s)+l(ak), where l(ak) is a rational approximation of log2 1/p(ak), p(ak) being the a'priori probability of occurrence of ak, and l(ak) being so constrained that the Kraft inequality is satisfied: AND FORMING C(sak) from the recursion C(s)+[Pk-12L(sak)],where: AND WHERE Pk-1 is the cumulative probability of occurrence of an arbitrary ordering of all symbols.

公开(公告)号：DE2966842D1

公开(公告)日：1984-04-26

申请号：DE2966842

申请日：1979-12-10

Applicant: IBM

Inventor： LANGDON GLEN GEORGE ,  MANTEY PATRICK EDWARD

IPC: G06T11/00 ,  G06T15/50 ,  G09G3/38 ,  G09G5/00 ,  G09G5/02 ,  G09G5/06 ,  G09G3/34 ,  H04N9/00

公开(公告)号：DE3278850D1

公开(公告)日：1988-09-01

申请号：DE3278850

申请日：1982-09-16

Applicant: IBM

Inventor： LANGDON GLEN GEORGE ,  RISSANEN JORMA JOHANNES

IPC: G06F5/00 ,  H03M7/40 ,  H03M7/42 ,  H04L23/00

公开(公告)号：DE3071383D1

公开(公告)日：1986-03-13

申请号：DE3071383

申请日：1980-06-13

Applicant: IBM

Inventor： LANGDON GLEN GEORGE ,  RISSANEN JORMA JOHANNES

IPC: G06F7/50 ,  G06T9/00 ,  H03M7/40 ,  H04L1/00 ,  H04L23/00 ,  H03M7/00 ,  G06F5/00