Overlapped field detecting apparatus capable of detecting non-overlapped fields mostly overlapped

摘要

In an overlapped field detecting apparatus, a delay unit delays a video signal, and a subtracter calculates a difference between the video signal and an output signal of the delay unit on a pixel-by-pixel basis. Also, an absolute value circuit calculates an absolute value of the difference on a pixel-by-pixel basis. Further, at least one comparator compares the absolute value of the difference with a threshold value on a pixel-by-pixel basis, and at least one accumulator counts a number of pixels when the absolute value of the difference is larger than the threshold value. A determination unit determines whether or not the number of pixels is larger than a definite value, thus determining that corresponding fields of two successive frames of the video signal are non-overlapped.