The iterative phase retrieval algorithm, called the Gerchberg-Saxton (GS) algorithm, is widely used to remove the speckle noise of holograms. Since the GS algorithm requires multiple diffraction calculations, it requires a large computation time. Another scheme, called the random phase-free method, uses virtual spherical waves instead of a random phase to diffuse reconstructed light. However, since ringing artifacts are conspicuous in this approach, an iterative phase retrieval algorithm must be used to remove them. In this paper, we proposed a phase porting method as a high-speed technique that utilizes the characteristics of ringing artifacts. We also compared the proposed method with existing methods in terms of calculation time and the image quality of the reconstructed images.
