1. An imaging system comprising: an imaging lens that is adjustable to different focal lengths; an image sensor configured to receive image information from the imaging lens; a mechanism to change a lens focal position during duration of a single image frame exposure of the image sensor; and processing circuitry configured to: enhance sharp image contents from an image captured by the image sensor; and obtain a distance map from one or more images captured by the image sensor while changing the lens focal position during an exposure of the one or more images.