| 摘要 |
PURPOSE:To save the memory capacity to detect the movement of a picture and to reduce malfunction of movement detection due to noise by using only a low frequency component of a luminance signal so as to obtain an inter-frame difference signal. CONSTITUTION:After a low frequency component of an existing frame Fa outputted from a low pass filter(LPF) 35 is subsampled by a subsampling circuit 41, the result is fed to a subtraction circuit 42. Moreover, a low frequency component of a preceding frame Fb outputted from an LPF 33 is subsampled by a subsampling circuit 43, retarded by a field delay circuit 44 and fed to the subtraction circuit 42. Then the subtraction circuit 42 applies subtraction processing to two input signals to obtain an inter-frame difference signal representing the movement of the picture. Thus, the memory capacity is saved and the movement of the picture is detected without being affected by noise. |
