Video compression domain target tracking method and system

The invention discloses a video compression domain target tracking method. The method comprises the following steps: extracting compression domain information corresponding to a first frame in a videosequence from a video bit stream that is obtained through compression coding of the video sequence, decoding the compression domain information to obtain a decoded image, and carrying out manual target marking on the image to obtain a target marking diagram of the first frame; carrying out parsing on the video bit stream so that a motion vector (MV) and a block coding mode corresponding to a frame next to a current frame in the video sequence are extracted from the video bit stream, and sequentially carrying out normalization processing and preprocessing on the obtained MV to obtain a processed MV of the next frame; and obtaining a target marking diagram of the next frame through a spatial-temporal Markov model. The method provided by the invention has the advantages that the technical problems in the conventional compression domain target tracking method that block level coding processing leads to low tracking accuracy and that as the number of the frames unceasingly increases, the tracking accuracy decreases frame by frame in a continuous and free-fall manner are solved.