1. A computer-implemented method of processing a digital image at a selected scale level, the method comprising: calculating a gradient map for a portion of the digital image greater than a size of a first preview area and including the first preview area; calculating a cumulative relative histogram for the gradient map for the portion of the digital image greater than the size of the first preview area and including the first preview area; selecting a location of the first preview area within the portion of the digital image greater than the size of the first preview area and including the first preview area; receiving a selected scale level to be used for an initial segmentation of the first preview area; (a) calculating a modified gradient map for the first preview area using the gradient map, the cumulative relative histogram and the selected scale level by determining from the cumulative relative histogram a threshold gradient value corresponding to the selected scale level and setting gradient values in the gradient map that are below the threshold gradient value to a minimum threshold; (b) segmenting the modified gradient map for the first preview area to create a first segmented preview image; (c) displaying the first segmented preview image; (d) receiving an indication of whether the first segmented preview image is acceptable; (e) receiving a new selected scale level and repeating steps (a)-(d) using the new selected scale level as the selected scale level until the indication received in step (d) indicates that the first segmented preview image is acceptable; and (f) segmenting the portion of the digital image greater than the size of the first preview area and including the first preview area using the selected scale level used when the indication in step (d) indicates that the first segmented preview image is acceptable.