| 摘要 |
A progressive scanner embodying the present invention improves the image quality of a television display by reducing the amount of adverse effects caused by interlace scanning. First, the incoming interlaced video signals of two successive fields are sub-sampled with spatial offset from each other, and the data rate and the picture elements are reduced by half. Second, the vertical resolution is doubled and the adverse effects removed. This is accomplished by generating interpolated signals with either a line memory or a field memory from the sub-sampled interlaced signals and creating a progressive display form by interpolating the generated signals. Both the required memory and the operational frequency in the progressive scanner are reduced because the data rate is reduced by the sub-sampling process. The sub-sampling process reduces the picture elements by half while retaining the horizontal resolution. The resolution is kept intact by sub-sampling the signals and interpolating the generated signals with an offset result in a display form of a three dimensional pattern of five points, one is each corner of a box and one in the middle of a square known as the quincunx pattern. To prevent the introduction of error in high frequency analysis known as the aliasing effect, the bandwidth of the incoming interlaced video signals can be limited before sub-sampling.
|
