Figure 7

Result of square-tree decomposition performed on L _S from Figure 6 , where w (7) = 0*1/( M _s *N _s ), w (8) = 32*2/( M _s *N _s ), w (9) = 152*4/( M _s *N _s ), w (10) = 148*8/( M _s *N _s ) were obtained. Smaller squares exist in places of big brightness changes. Larger squares appropriately in places, where the image brightness does not change by more than the set threshold. The image is therefore divided into square areas within which the difference between the minimum and maximum values is below the set threshold. If the difference between these values (minimum and maximum) is greater than the threshold, then the area is further divided. The division is always made into four smaller (square) areas. This procedure is carried out until the area reaches the size of 1×1 and a further division is not possible, or if the criterion of permissible differences in brightness is met.