Backing color and luminance nonuniformity compensation

Claim 1

In a method for correcting a background scene and a foreground scene, generating by extrapolation approximate RGB levels of a colored backing in a semitransparent transition area between the backing and an edge of a subject caused by subject motion or poor focus, said generated RGB levels representing a clear backing in said transition area when inhibiting corrections are applied to a video signal to remove non uniformity of backing luminance and color, said method comprising the steps of: a) generating a control signal controlling the background scene level as a function of the luminance and visibility of the colored backing, b) generating processed video (PRV) by subtracting levels of the control signal matching the RGB levels in the color backing thereby reducing the colored backing to a black backing, c) automatically identifying the semitransparent transition area as those pixels in which PRV>0, E c >0, d) identifying an unobscured colored backing area as those pixels in which PRV=0, E c >0, e) identifying an opaque subject area as those pixels in which PRV>0, E c =0, f) extrapolating the RGB levels from said unobscured colored backing area into said transition area, g) terminating the extrapolation process at an opaque subject boundary identified as PRV>0, E c =0, thereby generating backing RGB levels in the transition area that approximate the RGB levels that existed prior to the presence of the subject, said generated RGB levels stored in a clear frame memory.