US Patent 7312806 Dynamic width adjustment for detail-in-context lenses

A method for reducing occlusion in a presentation of a region-of-interest of an original image, the presentation generated by distorting the original image to produce a lens having a focal region for the region-of-interest at least partially surrounded by a shoulder region defined by a shoulder drop-of function, comprising: scaling the focal region; and, for an input point in the shoulder region, determining a width for the shoulder region from a distance between a projection point for the input point to the focal region and an intersection point on a perimeter of the lens of a line constructed through the input point, the projection point, and the intersection point, to thereby reduce occlusion of the shoulder region by the focal region.