Estimating optical characteristics of a camera component using sharpness sweep data

• Main Author: RUKES JASON R
• Format: Patent
• Language: English
• Published: 29.04.2014
• Subjects: ACCESSORIES THEREFOR; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES; APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM; CINEMATOGRAPHY; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; ELECTROGRAPHY; HOLOGRAPHY; PHOTOGRAPHY; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION

The sharpness sweep of a camera lens is performed while capturing several digital images of an object through the lens. The lens is swept in accordance with a range of distance-representing values. The images are analyzed to calculate a respective sharpness variable for each of several different regions of interest. For each region of interest, a peak value of the sharpness variable is found, as well as the distance-representing value associated with the peak. The pixel coordinates of each region of interest are converted into a pair of distance coordinates, which become part of a triple that is created for the region of interest and that also includes the associated distance-representing value. A surface to fit the triples is estimated, and a measure of the optical characteristic is computed using the estimated surface. Optical characteristics that may be estimated in this manner include tilt and curvature of field. Other embodiments are also described and claimed.