This paper presents the steps of reconstructing a 2-dimensional grayscale image using Moir technique. First, the 2D image was encoded with a halftone screen and turned into a halftone-screen image fA(u,v); Secondly the image fA and 1-fA (the reversed image of fA) were encoded by two gratings respectively, while keeping the frequencies of the two gratings the same and the phase difference being π. The angle between the encoding directions of the first and second steps is set to 45° so that the noise of the longitudinal Moiré fringes can be avoided. This technique can be applied for anti-counterfeit purpose.