US Patent 7471829 System and method providing subpixel-edge-offset-based determination of opacity

A system is provided for selecting a foreground region of an image, given a set of pixels defining the boundary of the foreground region of the image. The system includes a component to determine a foreground value (F) and opacity value (α) for each pixel on the set wherein α is determined via a subpixel edge-offset to facilitate a separation the foreground region from background portions of the image. The foreground value (F) and opacity value (α) are then employed to smoothly mix the foreground region of the image with a subsequent image background region.