Patent ID: 8717491

Claim:
An auto focusing method comprising: determining a current position of a focus lens before moving the focus lens; determining whether a first image input at the current position of the focus lens has image blurring using a histogram distribution of the first image; if the current position of the focus lens is a position for close range focusing and the first image has image blurring, determining that a motion direction of the focus lens is toward longer range focusing; if the current position of the focus lens is a position for long range focusing and the first image has image blurring, determining that the motion direction of the focus lens is toward closer range focusing; if the current position of the focus lens is the close range position and the first image does not have image blurring, determining that the motion direction of the focus lens is toward closer range focusing; and if the current position of the focus lens is the long range position and the first image does not have image blurring, determining that the motion direction of the focus lens is toward longer range focusing.