1. A computer-based method for generating a three dimensional (3D) image from a two dimensional (2D) image, comprising: retrieving a digitized 2D image from memory for use as a primary eye image; based on user input received via a user input device, selecting an object in the 2D image; in memory, storing the selected object as a base image; with an erosion engine implemented by a processor, eroding the selected object to generate a set of eroded versions of the base image corresponding to at least two erosion levels, wherein each of the eroded versions is reduced in size relative to the base image and to a previous one of the erosion levels; operating the processor to generate an alternate eye image by combining the base image with the set of eroded versions of the base image; storing the primary eye image and the alternate eye image in the memory for use in generating a 3D display; and determining a parallax shift value for each of the eroded versions of the base image, wherein each of the eroded versions of the base image is horizontally offset relative to the base image by a corresponding one of the parallax shift values, and each of the eroded versions of the base image is placed upon the base image or a preceding one of the eroded versions to generate the alternate eye image that is used with the primary eye image in the 3D display.