Automatically Locating an Area of interest and Maintaining a Reference Image to Aid the Real-Time Tracking of Objects

Real-time tracking systems often make use of a reference image and, where processing power is limited, an 'area of interest'. To obtain such information commonly requires user interaction. Typically, a reference image is obtained by the user capturing an image when the objects being tracked are not present in the scene and an 'area of interest' may also be defined by the user; both being specific to a particular scene. An alternative approach that would automatically generate and maintainn an up-to-date reference image is investigated in this paper. This consists of, essentially, 'cutting and pasting' areas of image from a sequence of frames to obtain an image containing no moving objects. Furthermore, a method for automatically generating an 'area of interest' is described. This method identifies areas of movement in a sequence of frames in order to build the 'area of interest'. These techniques have been successfully developed and proven using video sequences of more than one traffic roundabout.