Patent ID: 8223846

Claim:
A spatial error concealment (SEC) method, for concealing a spatial image error of an image frame in a image transmission system caused by a damaged macroblock (MB), and the system comprises a processor, a video buffer, and a memory which stories image frames wherein the image frame comprises a plurality of MBs with each of the MBs comprising a plurality of pixels, and the damaged MB contains incorrect image content, the SEC method comprising: loading the plurality of MBs from said memory into said video buffer, and performing the following steps with a processor: selecting an edge reference pixel group constituted by a plurality of N-pixel-wide edge reference pixels surrounding the damaged MB stored in said video buffer; partitioning the edge reference pixel group into a plurality of N×N-pixel edge reference blocks; using a Sobel operator to calculating directional gradients and directional angles of the pixels of the edge reference blocks; using a directional entropy calculation equation comprising a directional probability density function to calculate a directional entropy H d of the edge reference block according to the directional gradients and the directional angles of the pixels of the edge reference blocks; using a direction threshold equation to calculate a direction threshold β of the edge reference blocks, according to the directional entropy H d of all of the edge reference blocks; using a reference direction threshold to compare with the direction threshold of the edge reference blocks, and when the direction threshold is smaller than the reference direction threshold, adopting directions of the edge reference blocks, or otherwise determining the edge reference blocks as having no directivity; classifying the edge reference blocks into four categories according to the direction threshold, comprising no-directional background area, single-directional edge area, multi-directional edge area, and complex multi-directional edge area; using bi-linear interpolation (BI) method for compensation processing the no-directional background area, for obtaining image content of each pixel of the damaged MB; using directional interpolation (DI) method for compensation processing the single-directional edge area, for obtaining image content of each pixel of the damaged MB; using multi-directional interpolation (MDI) method for compensation processing the multi-directional edge area, for obtaining image content of each pixel of the damaged MB; and using a best neighborhood matching (BNM) method for compensation processing the complex multi-directional edge area, for obtaining image content of each pixel of the damaged MB, wherein the reference direction threshold is a real number ranging between 0.7 and 0.9.