Patent · US Active

Systems and methods for randomly accessing compressed images

US8107754B2 · kind B2 · utility

8Cited by
10References
27Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 7, 2007
Grant dateJan 31, 2012
Priority date
Expiry dateNov 29, 2030

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N19/93
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An embodiment of a method for encoding a source image comprising multiple data units, performed by an image encoding unit, comprises the following steps. A quantized DC coefficient and multiple AC coefficients of a data unit are generated. A value at the (0,0) element of the first data unit is determined according to the quantized DC coefficient. A variable length coding (VLC) stream of the data unit is generated by encoding the determined value and the AC coefficients. An encoded bitstream comprising a restart mark followed by the VLC stream of the data unit is generated. An offset pointing to the beginning of the restart mark of the encoded bitstream is stored in a random access table. A compression image comprising the encoded bitstream and the random access table is generated.

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