In order to eliminate the speckle noise in the reconstructed image of digital holography, on the basis of retaining the image details as much as possible at the same time of reducing noise, a method of image edge keeping and speckle noise denoising based on wavelet transform is proposed. It analyzes the principle of wavelet modulus maxima used in image edge detection and wavelet threshold denoising based on Neyman-Pearson criterion. A kind of speckle noise reduction method in the reconstructed image of digi...