The embodiments of the invention relate to automatic focusing methods and apparatus suitable for use in digital imaging devices. The proposed methods and apparatus evaluate the focus condition of the optical system by evaluating the digitized image, without requiring additional hardware besides the digital image-capture signal flow path. A method for computing the appropriate direction and magnitude of optical system adjustment, based on the evaluated focus condition, is provided. The computed quantities are communicated to the lens driving apparatus to reposition and adjust the optical system and to incrementally obtain a better focus. Upon reaching a desired focus quality, the device is prevented from controlling the lens driving apparatus.