1. A method of image processing for finding a target in a scene comprising: by one or more processors: receiving a series of images from a sensor; computing a background relative velocity in the series of images; hypothesizing a target relative velocity of the target in the series of images; computing a target revisit time based on a difference of the hypothesized target relative velocity and the background relative velocity; and adjusting one or more of a frame capture rate of the sensor or a frame processing rate based on the target revisit time.