 image. This is based on an autofocus approach in which a focus function is used to give quantitative assessment of the image sharpness. </p>

<p>There is a large body of literature concerning the quantification of image sharpness. In general, a sharp image will contain more high-frequency information than its blurry counterpart, however, there is no universally accepted measure for this difference. A variety of sharpness metrics (or equivalently, focus functions) have been proposed, including those based o