Patent ID: 7969501

Claim:
A method of auto-focusing within an image sensing system, the method comprising: generating by a digital signal processor an N-bin luminance histogram from an image; determining by a microprocessor a type of the image from the N-bin luminance histogram; determining by the microprocessor a focus position using a first set of at least one focus value if the image is determined to be of a first type; determining by the microprocessor the focus position using a second set of at least one focus value different from the first set if the image is determined to be of a second type; determining by the microprocessor a K-th bin satisfying ∑ i = K N - 1 ⁢ H i ≥ H N , wherein H i is a respective histogram value for each i-th bin, and wherein H N is a respective histogram value for the N-th bin that is for a brightest luminance; determining by the microprocessor a distance D=(N−K) for the K-th and N-th bins; determining by the microprocessor that the image is of a highlight scene type if the distance D is greater than or equal to a reference value; and determining by the microprocessor that the image is of a normal scene type if the distance D is less than the reference value.