What are interlace and progressive scanning?
There are two dominant interlaced scan systems: NTSC and PAL. Interlaced scanning has served the analog camera and television world very well for many years. It made up of 576 visible horizontal lines across a standard TV screen. Interlacing divides these into odd and even lines and then refreshes them in an alternate order (lines or rows 1,3,5, etc… followed by lines or rows 2,4,6) Progressive scan differs from interlaced scan in that the image is displayed on a screen by scanning each line (or row of pixels) in a sequential order rather than an alternate order, as is done with interlaced scan. In other words, in progressive scan, the image lines (or pixel rows) are scanned in numerical order (1,2,3) down the screen from top to bottom.
