However, the readability of the numbers on the chart is at least as good as in the 600-line filtered image. The readability is much better than the image filtered at the Nyquist limit. If a scene had a very fine picket fence with a resolution above the Nyquist limit, it would have the wrong number of pickets. However, at just below the Nyquist limit, the number would be correct. System improvements The simplest way to achieve the benefits of progressive scan is obviously to use a progressive camera, a compression system designed for this and a progressive display.
Progressive displays are now readily available.
A compression system designed for this format does not exist in the 18 ATSC broadcast formats. Consequently, other strategies need to be used in the short term. This eliminates the visible field line structure but it does not reduce interline flicker caused by the alias frequencies generated by interlace. There will be no line structure for motion at the line crawl speed, making the resolution under these conditions appear to be somewhat better. This system takes advantage of the fact that our visual systems have a slow response to detail and motion detection is done at low resolution.