Extending a digital camera focus range

摘要

A method for controlling a digital camera system having an optical system with an F/# that can be varied between a minimum F/# and a maximum F/#, comprising: setting the optical system F/# to a first F/#; capturing an evaluation image of the scene; analyzing the evaluation image to determine whether a subject is acceptably focused; if the subject is acceptably focused setting a capture F/# to be equal to the first F/#, otherwise the optical system F/# is iteratively increased until the subject is determined to be acceptably focused, or until a maximum F/# is reached; determining a capture F/# responsive to the F/# where the subject is acceptably focused; setting the optical system to use the capture F/#; capturing an archival image of the scene using the image sensor; and storing the captured archival image in a storage memory.

主权项

1. A method for providing an extended focus range, comprising:
a) setting an F/# of an optical system of a digital camera to a first F/#, wherein F/# represents the ratio of the optical system's focal length to aperture size, and wherein the first F/# is larger than or equal to a minimum F/# of the optical system and smaller than or equal to a maximum F/# of the optical system; b) capturing an evaluation image of a scene using an image sensor of the optical system; c) analyzing the captured evaluation image to determine whether a subject in the captured evaluation image is acceptably focused; d) setting a capture F/# to be equal to the first F/# if the subject in the captured evaluation image is acceptably focused; otherwise
i) increasing the F/# of the optical system;ii) capturing an additional evaluation image of the scene using the image sensor and the increased F/#,iii) analyzing the captured additional evaluation image to determine whether the subject in the captured additional evaluation image is acceptably focused,iv) repeating steps i) through iii) until the subject in the captured additional evaluation image is determined to be acceptably focused, or until the maximum F/# is reached, andv). determining a capture F/# responsive to step iv); e) setting the optical system to use the capture F/#; f) capturing an archival image of the scene using the image sensor and the capture F/#; and g) storing the captured archival image in a storage memory.