Inverse problem approach for particle digital holography: accurate location based on local optimisation

Abstract : This paper proposes a new micro-particles localization scheme in digital holography. Most conventionnal digital holography methods, are based on Fresnel transform and have several issues such as twin-image, border effects... To avoid these difficulties, we propose an inverse problem approach, which yields the optimal particles set which best models the observed hologram image. We resolve this global optimization problem by conventional particle detection followed by a local refinement for each particle. Results on both simulated and real digital holograms show strong improvements in the localization of the particles, in particular along the depth dimension. In our simulations, the position precision is about or better than 1 µm rms. Our results also show that the localization precision does not deteriorate for particles near the edges of the field of view.