Patent · US Expired

Post-filtering for decoded video signals

US5590064A · kind A · utility

120Cited by
9References
30Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 26, 1994
Grant dateDec 31, 1996
Priority date
Expiry dateOct 26, 2014

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N11/044
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

Encoded video signals comprise sets of transform coefficients (e.g., DCT coefficients) corresponding to different regions of a video frame. An inverse transform is applied to sets of transform coefficients to generate decoded regions of a decoded video frame. The discontinuities for boundaries between adjacent regions are used to adjust one or more of the transform coefficients. The adjusted sets of transform coefficients are then used to generate filtered regions of a filtered video frame corresponding to the decoded video frame. In a preferred embodiment, the transform coefficients are DCT coefficients and the DC and first two AC DCT coefficients are sequentially adjusted to correct for quantization errors in the encoding process.

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