Abstract: An image is focused onto an image sensor array by efficient movement of an adjustable focus lens by a lens focus motor. A minimum of three focus positions is required to determine an estimated best focus position of the lens focus motor. After which a sweep of the focus positions surrounding the estimated best focus position is performed to verify and determine the best actual focus position of the lens focus motor. A sharpness value of the image being focused comprising a Sobel edge detection or other detections means provide sharpness data to evaluate image sharpness at various lens focus motor positions.

Abstract: An image is focused onto an image sensor array by efficient movement of an adjustable focus lens by a lens focus motor. A minimum of three focus positions is required to determine an estimated best focus position of the lens focus motor. After which a sweep of the focus positions surrounding the estimated best focus position is performed to verify and determine the best actual focus position of the lens focus motor. A sharpness value of the image being focused comprising a Sobel edge detection or other detections means provide sharpness data to evaluate image sharpness at various lens focus motor positions.

Abstract: A focus motor of a digital camera is moved to a point of focus from which image data is integrated and evaluated for sharpness and luminance. When the focus motor is stopped, a delay is initiated to allow integration of the image data from which a Sobel value and a luminance value are determined to allow the calculation of a focus value to be calculated from the ratio of the Sobel value to the luminance value. Once the focus value is calculated, the next motor position is determined from which a next focus value is determined.