A Speckle Noise Suppression Method Based on Quality Map

Digital holography is a technique for measuring the shape of an object in 3D. It uses interference patterns generated by a laser or other light source, which record both the phase and intensity information of the light reflected from the surface of the object. This information is then encoded into digital holograms and reconstructed using computational methods to produce a 3D shape of the object. In the process of digital holography measurement, due to the high coherence of the laser, a large amount of speckle noise is generated when measuring rough surfaces due to diffuse reflection, leading to errors in the reconstruction results. Although traditional phase filtering has a good effect on noise filtering, it may cause distortion of normal phase. In order to suppress speckle noise, this study compared the common quality maps, proposed a local threshold adaptive speckle noise extraction method based on quality maps, and finally obtained the correct phase map by restoring the speckle noise points.