| 摘要 |
Substantially removing shadows in video images obtained from a camera viewing a scene, at variable pointing angles and magnification, by digital processing of a sequence of frames in the video signal, the processing including - (a) creating and maintaining a model image of the scene, by accumulating image data from a plurality of video frames; (b) in the model image, detecting and defining model shadow zones; (c) calculating correction factors for the model shadow zones; (d) for each frame of the video signal - defining, in the image carried by the signal, shadow zones that correspond to respective model shadow zones; and (e) correcting video signal values in shadow zones accordingly. |
