Patent · US Expired

Apparatus for decoding variable-length encoded data

US4967196A · kind A · utility

16Cited by
9References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 31, 1988
Grant dateOct 30, 1990
Priority date
Expiry dateMar 31, 2008

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03M7/425
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

Digital image data is encoded using a variable-length code which is described by a group of parameter values. Each parameter value describes a set of code values; each code value corresponds to a possible value of the data which is to be encoded. When the data is encoded, the parameter values are appended to the encoded data. A decoder stores the parameter values into a memory and then combines data values derived from the encoded data with parameter values from the memory to generate decoded data values. Each code word includes a prefix which indicates a number of successive parameter values which are to be summed, and a population index which is to be added to the summed parameter values to produce a decoded data value.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.