Interpretation of moiré phenomenon in the image domain.

We propose an interpretation of moiré phenomenon in the image domain. The interpretation is basically based on the analysis of the waveform of the line families. The period, angle, and intensity profile of moiré fringes can be obtained directly in the image domain according to this interpretation. Moreover, pseudo-moiré can be interpreted visually with the consideration of the illusional contrast of the human visual system. The interpretation, which is consistent with the Fourier theory when the two superposed gratings are periodic, involves only the image domain and shows remarkable simplicity, just like the indicial equation method.