Patent ID: 8169532
Filing Date: 2012-05-01
Classification: H04N

Abstract:
1. A distance measuring method for use in a portable electronic device having an auto focus function, said portable electronic device comprising an image pickup module, said image pickup module having a lens, said distance measuring method comprising steps of: establishing a distance look-up table by correlating a plurality of lens moving step numbers with corresponding object distance values; performing said auto focus function to capture an image of an object by said image pickup module of said portable electronic device, thereby obtaining a current lens moving step number required for performing said auto focus function; and acquiring a current object distance value corresponding to said current lens moving step number according to said distance look-up table, wherein said distance look-up table includes a near distance threshold value, wherein if said current lens moving step number is larger than said near distance threshold value, said current object distance value corresponding to said current lens moving step number is acquired according to a Gaussian imaging formula, and if said current lens moving step number is smaller than or equal to said near distance threshold value, said current object distance value corresponding to said current lens moving step number is acquired according to a practical measurement.