Whats the difference between interlaced and progressive scanning?
Interlaced scanning shows half of an image (on the odd rows of pixels) every sixtieth of a second, and then it shows the other half (on the even rows) the next sixtieth. Therefore, it takes one thirtieth of a second to show a complete frame, giving a framerate of 30 frames per second. Progressive scanning shows the entire image every sixtieth of a second, so the framerate is twice as high – 60 frames per second. Therefore, progressive scanning creates a smoother image, and is preferable if you have a choice.
Augumenting the earlier response, interlaced beam scanning is the electron beam (in CRT tubes) “painting” every other line of a picture on the first top-to-bottom sweep, then jumping back to the top and filling in the skipped lines. Progressive (non-interlaced) scanning paints every line in sequence (top-to-bottom) every sweep.
