Contrast detection is one of the two main techniques used in camera autofocus systems. Although focusing speeds continue to improve, the method uses an inefficient “guess and check” method of figuring out a subject’s distance — it doesn’t initially know whether to move focus backward or forward. UT Austin vision researcher Johannes Burge wondered why the human eye is able to instantly focus without the tedious “focus hunting” done by AF systems. He and his advisor then developed a computer algorithm that’s able determine the exact amount of focus error by simply examining features in a scene.
His research paper, published earlier this month, offers proof that there is enough information in a static image to calculate whether the focus is too far or too close. Burge has already patented the technology, which he says could allow for cameras to focus in as little as 10 milliseconds.