Patent ID: 7330586

Claim:
A method for locating one or more regions of interest in a frame sequence defined by a plurality of pixel locations, each of which includes a corresponding pixel from each frame in the sequence, based on color information at each pixel location that is stored in a data structure having as a mathematical construct a collection of spheres, each of which includes a center value, the method comprising: (a) initializing the center value of a first sphere associated with a given pixel location to a color value of the corresponding pixel in a first frame; and (b) examining a color value of the pixel in each subsequent frame corresponding to the given pixel location to determine which, if any, of the first sphere or any other sphere created the value of that pixel lies, such that (b)(1) if a currently examined pixel lies within only one of the spheres, the center value of that sphere is updated to take into account the color value of the currently examined pixel, (b)(2) if the currently examined pixel lies within multiple spheres, the center values of such spheres are updated, taking into account respective weighted portions of the color value of the currently examined pixel, and (b)(3) if the currently examined pixel does not lie within any sphere currently in existence, a new sphere is created with its center value being set as the color value of the currently examined pixel; wherein, after all pixels at the given pixel location are examined, each sphere associated with the given pixel location stores color information obtained from pixels at the given pixel location.