1. A computer program embodied in a non-transitory computer-readable medium for effecting the performance of a method of encoding a sequence of sets of image region modeling coefficients representing respective regions of an image into a sequence of reordered sets of image region modeling coefficients by repeatedly determining which of a plurality of different scan orders to use, said method comprising: a. using a predetermined one of the scan orders to scan a plurality of the image region modeling coefficients representing a respective region of the image; b. based on information from the already-scanned plurality of image region modeling coefficients, determining whether a different one of the scan orders has a higher probability of effectively encoding successive image region modeling coefficients representing another respective region of the image; c. if said probability is higher, using said different scan order for encoding the successive image region modeling coefficients; and d. repeatedly performing steps b and c for already-scanned modeling coefficients and yet-to-be-scanned modeling coefficients, respectively.