Automatic estimation of the focusing reconstruction distance of recorded object in digital holography

In this paper, a method which can effectively achieve the accurate estimation of the focusing reconstruction distance of recorded object in digital holography (DH) is proposed. By analyzing the variance variety of the reconstructed intensity images corresponding to different reconstruction distances, the accurate focusing reconstruction distance of the recorded object is obtained and thus the legible reconstructed image in-focus is acquired. The effectiveness of the proposed method is successfully validated with both pure phase objects and pure amplitude objects in experiment. This method will have great potential application foreword in digital holographic measurement field.