Thursday, September 4, 2008

A better understanding of Interlace


This animation demonstrates the interline twitter effect. The two interlaced images use half the bandwidth of the progressive one. The interlaced scan (second from left) precisely duplicates the pixels of the progressive image (far left), but interlace causes details to twitter. Real interlaced video blurs such details to prevent twitter, as seen in the third image from the left, but such softening (or anti-aliasing) comes at the cost of resolution. A line doubler could never restore the third image to the full resolution of the progressive image.

Note – Because the frame rate has been slowed down, you will notice additional flicker in simulated interlaced portions of this image.

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