Patent ID: 7701470

Claim:
A computer-implemented method, comprising: performing by a computer: generating a first raster image mask in a digital image, wherein the first raster image mask comprises a first set of one or more pixels having a first intermediate value for membership in the first raster image mask, wherein the first intermediate value is less than a maximum value for membership in the first raster image mask and greater than a minimum value for membership in the first raster image mask; generating a second raster image mask in the digital image, wherein the second raster image mask comprises the first set of one or more pixels having a second intermediate value for membership in the second raster image mask, wherein the second intermediate value is less than a maximum value for membership in the second raster image mask and greater than a minimum value for membership in the second raster image mask; and combining the first raster image mask and the second raster image mask to generate a third raster image mask in the digital image, wherein a boundary of the third raster image mask is not greater than a combined boundary of the first raster image mask and the second raster image mask.