Linear system based, qualitative independent motion detection from compressed MPEG surveillance video

摘要

The present invention features a qualitative method to detect independent motion revealed in successive frames of a compressed surveillance MPEG video stream using linear system consistency analysis without decompression of the stream, identifying the segments containing independent motion in a real-time or faster manner, for the retrieval of these segments. The linear system is constructed using the macroblocks of MPEG compressed video frames. The normal flow value of the macroblock is obtained by taking the dot product between the macroblock gradient vector, computed by averaging the four block gradient vectors, and the motion vector of this macroblock. The normal flow value is filtered for inclusion in the linear system, and the statistic of the matrices of the resulting linear system is determined, filtered to screen out false negatives and outliers, and used to determine the presence or absence of independent motion.

主权项

1. A method for detection of independent motion of a plurality of objects presented in a plurality of images acquired at different spatial positions, comprising:
a) processing each of the plurality of images with an automated processor to generate a respective linear system representing the plurality of objects in the form of a matrix having at least three dimensions stored in a memory; b) analyzing a plurality of matrices with an automated processor to qualitatively determine whether there is a unique solution for the plurality of matrices as representing a respective linear system, based on a ratio of a singular value decomposition of a matrix with respect to an associated augmented matrix, wherein:
{dot over (x)}+θ{dot over (y)}+αx+βy+y=0 represents a linear constraint for each point at coordinates (x,y) with derivatives {dot over (x)}, {dot over (y)}, represented in respective images, wherein α, β, γ, and θ are functions of both the motion parameters and affine transform parameters between respective images; and c) outputting a signal corresponding to the qualitative determination, representing whether or not there is independent motion between the plurality of objects represented in the time sequence of images.