×

Method and apparatus for concealing errors in a transmitted video signal

  • US 5,936,674 A
  • Filed: 12/23/1996
  • Issued: 08/10/1999
  • Est. Priority Date: 12/23/1995
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method for concealing channel errors in an image signal, wherein the image signal is divided into a multiplicity of blocks of M×

  • N pixels, M and N being positive integers, respectively, the method comprising the steps of;

    (a) detecting a lost region, wherein the lost region is of a polygonal form having a plurality of sides and includes one or more connected lost blocks, each lost block containing a channel error;

    (b) finding a reference region of pixels, wherein the reference region includes a plurality of groups of first pixels and a corresponding number of groups of second pixels, each group of first pixels being adjacent to a side of the lost region and each group of second pixels being adjacent to a group of first pixels, each group of first pixels being placed between a group of second pixels and the lost region;

    (c) determining edge pixels among the pixels within the reference region, each edge pixel having a non-zero valued edge magnitude, the edge magnitude for an edge pixel representing differences between pixels residing adjacent to the edge pixel;

    (d) detecting edge points, each of the edge points representing an edge pixel having a largest edge magnitude among edge pixels included in a group of first pixels and a group of second pixels for a side of the lost region; and

    (e) rectifying the channel errors of the lost region by compensating all pixels within the lost region based on the edge points and the pixels of the reference region;

    wherein said rectifying step includes the steps of;

    (e1) if two or more edge points are detected, determining two edge points of a first and second largest edge magnitudes as primary edge points and dividing the lost region into two or more subregions by a primary line passing through the primary edge points;

    (e2) if fewer than two edge points are deleted, setting the lost region itself as a subregion; and

    (e3) rectifying the channel errors by compensating pixels within each subregion based on the pixels of the reference region.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×