Realization of Absolute-Phase Unwrapping and Speckle Suppression in Laser Digital Holography

In this paper, an absolute-phase unwrapping and speckle suppression approach to reconstruct a three-dimensional (3-D) image of an object with laser digital holography is described. This method offers three advantages to enhance the performance of the phase reconstruction technique. First, both speckle suppression and phase unwrapping are processed in the complex amplitude domain rather than in the single phase or amplitude domain. With this approach, the phase details of the object are better preserved upon phase reconstruction. Second, the proposed algorithm requires no threshold determination and thus achieves self-adaptive speckle suppression and robust phase unwrapping, in contrast to other methods. Finally, an improved dual-domain image denoising method is applied to further remove speckle-remnant-induced phase distortion. Ideal 3-D phase reconstruction results are obtained both theoretically and experimentally for the first time.