Single exposure 3-D object digital holography based on multi-filtering technique

For improving the quality of the reconstructed image calculated from the hologram,a 3-D object digital hologram was successfully recorded by using single exposure method and 3-D object holographic optical setup based on Mach-Zehnder interferometer.The quality of the reconstructed image directly calculated from the recorded hologram was unsatisfactory because of the presence of the zero-order diffraction and the speckle noise.A set of digital image processing algorithms was then proposed to process the digital hologram and the reconstructed image with multi-filtering technique.The method synthetizing the wavelet filtering and the contracted weighted mean filtering is capable to eliminate the zero-order diffraction component and reduce the speckle noise to obtain realistic reconstructed image.The experimental result shows that this simple method is very effective for improving the quality of the reconstructed image.For recording hologram only once,it is convenient for application in the real time image processing fields.