Patent ID: 6891570
Filing Date: 2005-05-10
Classification: H04N

Abstract:
1. A method of adaptively determining the exposure time and frame rate for each frame captured by an image capture system of the type having an image sensor, optics for forming an image of a scene on the image sensor, and an image processor for determining an exposure time for the image sensor, said method comprising the steps of: a) acquiring two time-separated image frames during an initial exposure time set for each of the image frames, wherein each image frame includes one or more moving objects from the scene; b) spatially registering the two image frames; c) measuring spatial displacements between the two image frames for the same moving objects; d) determining a fastest moving object in the scene from the measured spatial displacements; e) calculating a speed of the fastest moving object; f) calculating object smear for the fastest moving object based on the initial exposure time; g) if the object smear exceeds a maximum desired smear, calculating a new exposure time; h) setting the exposure time for a subsequent image frame to the new exposure time; i) if the measured spatial displacement of the fastest moving object exceeds a maximum desired displacement, calculating a new frame rate; and j) setting the frame rate for a subsequent image frame to the new frame rate.