The invention discloses a video content expressing method based on the significant element of space time, which is based on the mechanism of biological visual attention, and maps the former characteristic space into the illegible information granule space by the method of illegible information granulating, to realize the distinct analysis of visual information effectively and pick up the distinct region conforming to the vision features as the analysis body for time consistency of the subunit. On the base, the combination of sub units is conduct under the different impacts of distinction and background regions on the content description, to get the distinct space unit with consistent content. Experimental results show the effectiveness and semantic nature of the mode that distinct space unit pick up by the invention is taken as the video content. |