Autofocus system based on statistical data and method

The present invention provides a kind of autofocus system with camera lens and makes and using the method for the system.When executing focus operation, controller calculates the focus measurement value of each lens location in a plurality of lenses position.The focus measurement value is to calculate gained with corresponding flexible strategy based on each of the window evaluation value of image focusing window in one group of image focusing window.The controller then the focus measurement value obtained by the calculating of more the multiple lens location to select optimum lens position.Described image focusing window group can be selected based on the one or more groups of image focusing windows selection rule obtained from statistical data.In addition, may be based on the corresponding flexible strategy that the statistical data calculates image focusing window.