Patent ID: 6646687
Filing Date: 2003-11-11
Classification: H04N

Abstract:
A method for automatically defocusing a background scene including background pixels as said background scene is being composited with a foreground subject during the photography of said subject and where said background scene becomes increasingly defocused as said subject appears to approach the camera, and comprises the steps of;a) connecting a source of background image signals to the background input of a compositing device capable of averaging a selected group of background pixels, each of said background pixels having a signal level, b) connecting a source of foreground image signals to a foreground input of the compositing device, c) accessing a matte signal generated by said compositing device, d) using said matte signal to determine the ratio of foreground subject area to image frame area, e) using said area ratio to select, for each pixel in said background image, a number of adjacent pixels to be averaged to form an average pixel level f) replacing said signal level of said background pixels with said average pixel level, thereby defocusing said background scene in proportion to the apparent reduction in camera to subject distance.