Estimating optical characteristics of a camera component using sharpness sweep data

A method for estimating an optical characteristic of an autofocus lens, comprising:

• sweeping the autofocus lens while capturing, using an image sensor, a plurality of digital images of an object through the lens, wherein the autofocus lens is swept in accordance with a plurality of autofocus actuator driver values;
• analyzing the digital images to calculate a respective sharpness variable for each of a plurality of different regions of interest of the image sensor;
• for each of the regions of interest, finding a peak value of the respective sharpness variable and the autofocus actuator driver value associated with the peak value;
• for each of the regions of interest, converting the associated driver value to an associated lens displacement value, and converting pixel coordinates of each region of interest to a pair of distance coordinates, wherein a plurality of triples are created for the regions of interest, each triple containing the associated lens displacement value and the pair of distance coordinates;
• estimating a surface to fit the plurality of triples;
• and
• computing a measure of the optical characteristic of the autofocus lens using the estimated surface, wherein the computed measure comprises a normal vector to the estimated surface.

A method for estimating an optical characteristic, comprising:

• performing a sharpness sweep of a camera lens while capturing, using an image sensor, a plurality of digital images of an object through the lens, wherein the lens is swept in accordance with a plurality of distance-representing values, and the digital images are analyzed to calculate a respective sharpness variable for each of a plurality of different regions of interest in the image sensor;
• for each of the regions of interest, finding a peak value of the respective sharpness variable and the distance-representing value associated with the peak value;
• converting pixel coordinates of each region of interest to a pair of distance coordinates, wherein a plurality of triples are created for the plurality of regions of interest, respectively, each triple containing the associated distance-representing value and the pair of distance coordinates;
• estimating a surface to fit the plurality of triples, wherein the estimated surface is a plane;
• and
• computing a measure of the optical characteristic using the plane, wherein said computing the measure of the optical characteristic comprises computing a plurality of difference values, wherein each difference value is a difference between the plane and the associated distance-representing value of a respective one of the regions of interest.