Single-shot absolute 3D measurement based on speckle-embedded fringe projection

In this paper, we propose a single-shot absolute three-dimensional (3D) imaging method that only needs one speckle-embedded fringe pattern. In terms of algorithm, we develop a computational framework to achieve 3D measurement through: 1). extracting the fringe phase from speckle-embedded fringe images by performing a two-dimensional (2D) band-pass filtering on the Fourier spectrum; 2). utilizing the local speckle distribution to eliminate the periodic ambiguity of fringes and achieve integer-pixel matching; 3). utilizing the wrapped phase to refine the disparity map at the sub-pixel level. In terms of system setup, we design an optical system which can project a speckle-embedded fringe pattern in a large depth-of-field. The experiments are conducted to demonstrate the feasibility and effectiveness of the proposed method. The 3D measurement rate of our method is equal to the frame rate of cameras, not limited by projection devices.