摘要 |
<p>In a wavelet transform section, wavelet-transform coefficient signals are obtained by two-dimensional wavelet transformation, employing a low-pass filter which has a characteristic that its response at a frequency greater than a spatial frequency corresponding to grid pitch is approximately zero. Based on the direction of the grid judged by a direction judging section, a suppressing section applies one-dimensional wavelet transformation to a signal containing a grid component (when a vertical grid is used, signal HL1), in the grid direction. Then, alow frequency transform coefficient signal of the transform coefficient signals is made zero. The signal, made zero, and the remaining signals, are subjected to inverse one-dimensional wavelet transformation. In an inverse wavelet transform section, the original image is restored with a signal having a suppressed grid component.</p> |