1. A method of determining scene changes in a sequence of visual information-bearing frames, comprising the steps of: (a) dividing a first digitized frame into a first plurality of regions and a second digitized frame into a second plurality of regions that respectively correspond in location to the first plurality of regions; (b) block-matching the regions of the first digitized frame to the regions of the second digitized frame to produce regional match signals that represent a likelihood that the regions of the first digitized frame contain visual information substantially similar to respective matching regions of the second digitized frame; (c) ordering, to obtain an ordered sequence, the regional match signals beginning with a best regional match signal defining a best match and ending with a worst regional match signal defining a worst match; (d) averaging together a predetermined number of the regional match signals that are selected in the ordered sequence of step (c) beginning with the best match signal, to obtain an instantaneous match (IM) signal, said IM signal providing a criteria for determining whether the first digitized frame represents a scene different from a scene represented by the second digitized frame; and (e) indicating a scene change when the IM signal meets a predetermined decision criterion.