The drawback of this filter function is a ringing effect that occurs along the edges of the filtered spatial domain image. This phenomenon is illustrated in Figure 1, which shows the shape of the one-dimensional filter in both the frequency and spatial domains for two different values of Eqn:eqnfreq3. We obtain the shape of the two-dimensional filter by rotating these functions about the y-axis. As mentioned earlier, multiplication in the Fourier domain corresponds to a convolution in the spatial domain. Due to the multiple peaks of the ideal filter in the spatial domain, the filtered image produces ringing along intensity edges in the spatial domain.