Method and devices for restoring specific scene from accumulated image data, utilizing motion vector distributions over frame areas dissected into blocks

Disclosed is a method of restoring specific scene whose objectives are to provide a specific scene restoration system having a sufficient detection rate enough to easily detect and pick up the specific scene from a plenty number of video data, or to detect in real time such scene as those whereon specific motions exist, comprising the steps of dissecting into kxk=N blocks( where N is 100 or less, desirably an integer in the range of 9 to 36) each frame of a motion video signal wherein a series of specific scenes to be restored are contained, calculating the motion quantities in each block using the total sum of the motion vector magnitudes in each block, obtaining a Mahalanobis distance D2 for the images of said specific scenes, calculating a threshold defined by the average of D2 plus standard deviation of D2, comparing the threshold to the Mahalanobis distance D2 calculated for each frame of the motion video signal to be retrieved, and by detecting the specific scene to be obtained on condition that the Mahalanobis distance in the latter is decided