The definitive version is available at http://www.opticsinfobase.org/abstract.cfm?URI=josaa-24-4-1164International audienceThis 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...