A field delay circuit aligns the phases of two field signals. An average value calculation circuit generates an average value signal of the two field signals. This average value signal can be regarded as a signal that has undergone a one-dimensional low-pass filter process in the row direction in which the number of taps for a progressive signal is 2 and the filter coefficient for each tap is 0.5 and that has then been thinned to one-half the data. A two-dimensional LPF circuit subjects this average value signal to a low-pass filter process and eliminates the high-frequency components (edge components). A subtraction circuit subtracts the average value signal that has undergone the LPF process from each field signal and thus extracts the edge components of each field signal. An amplification circuit multiplies the edge components of each field signal by a prescribed factor. An addition circuit adds the resulting amplified edge components to each field signal.