Patent Document ID: 20030090505
Application ID: 10298968
Patent Status: 0

Claim One:
1. A system for detecting significant scenes and selecting keyframes of source video, comprising: a receiver which receives source video as macroblocks including blocks of DCT coefficients and frames; a summer which calculates a sum for each type of block within a macroblock based on: SUM&lsqb; I&rsqb;&equals; 3 k,j ABS ( DCT 1 k,j &lsqb;I&rsqb;−DCT 2 k,j &lsqb;I&rsqb; ) where: k is the number of macroblocks in width of a frame, k&equals;1 to Frame-width/16, j is the number of macroblocks in height of a frame, j&equals;1 to Frame-height/16, I is the number of blocks in a macroblock, I&equals;1 to number of blocks in macroblock, DCT1 k,j and DCT2 k,j are DCT coefficients for the specified macroblock for a previous and a current frame, respectively, and ABS is an absolute value function; a threshold adjustor which adjusts a first threshold and a second threshold based on the category of the source video, a first comparator for comparing each SUM&lsqb;i&rsqb; to the first and second thresholds and saving the current frame as a keyframe in a frame memory if SUM&lsqb;i&rsqb; is greater than the first threshold, incrementing a static scene counter if less than the second and saves the previous frame in a temporary memory, and resets the static scene counter otherwise; and a second comparator which compares the static scene counter to a predetermined number and transferring the most previous video frame saved in the temporary memory to the frame memory as a keyframe.