Patent ID: 6532022
Filing Date: 2003-03-11
Classification: G06T,G11B,H04N

Abstract:
A computer-implemented digital video object compositing method comprising:creating a background image model by examining a plurality of frames of an input image that does not contain an object to be composited; obtaining a frame of an input image that contains the object to be composited; creating an alpha image according to the input image that contains the object to be composited and the background image model; determining whether a portion of the input image that contains the object to be composited comprises a shadow, wherein the shadow is determined by assigning a color value to a pixel in the background image, assigning a brightness value to the pixel in the background image, comparing the color and brightness values assigned to a corresponding pixel in the input image that contains the object, and identifying the corresponding pixel as being in a shadow where the corresponding pixel color value is substantially unchanged and the corresponding pixel brightness value is substantially less than the brightness value of the pixel in the background image; transferring shadow information to the alpha image; deriving a set of templates comprising the shape of the object being composited, wherein the set of templates are derived from the alpha image; filling gaps in the alpha image according to the set of templates; and blending the object in the input image that contains the object onto a destination image using the alpha image, thereby compositing the object onto a destination image with reduced shadows and gaps in the object.