What is the difference between interlaced and progressive video?
There are basically two ways to display video: interlaced scan or progressive scan. Progressive scan, used in computer monitors and digital television, displays all the horizontal lines of a picture at one time, as a single frame. Interlaced scan, used in standard television formats NTSC, PAL, and SECAM, displays only half of the horizontal lines at a time (the first field, containing the odd-numbered lines, is displayed, followed by the second field, containing the even-numbered lines). Interlacing relies on the persistence of vision characteristic of our eyes (which may only be psychological, not physical), as well as the phosphor persistence of the TV tube to blur the fields together into a seemingly single picture. The advantage of interlaced video is that a high refresh rate (50 or 60 Hz) can be achieved with only half the amount of data. The disadvantage is that the horizontal resolution is essentially cut in half because the video is often filtered to avoid flicker and other art
There are basically two ways to display video: interlaced scan or progressive scan. Progressive scan, used in computer monitors and digital televisions, displays all the horizontal lines of a picture at one time as a single frame. Interlaced scan, used in standard television formats (NTSC, PAL, and SECAM), displays only half of the horizontal lines at a time (the first field, containing the odd-numbered lines, is displayed, followed by the second field, containing the even-numbered lines). Interlacing relies on phosphor persistence of the TV tube to blend the fields together over a fraction of a second into a seemingly single picture. The advantage of interlaced video is that a high refresh rate (50 or 60 Hz) can be achieved with only half the bandwidth. The disadvantage is that the vertical resolution is essentially cut in half, and the video is often filtered to avoid flicker (interfield twitter) and other artifacts.
There are basically two ways to display video: interlaced scan or progressive scan. Progressive scan, used in computer monitors and digital television, displays all the horizontal lines of a picture at one time, as a single frame. Interlaced scan, used in standard television formats NTSC, PAL, and SECAM, displays only half of the horizontal lines at a time (the first field, containing the odd-numbered lines, is displayed, followed by the second field, containing the even-numbered lines). Interlacing relies on the persistence of vision characteristic of our eyes (which may only be psychological, not physical), as well as the phosphor persistence of the TV tube to blur the fields together into a seemingly single picture. The advantage of interlaced video is that a high refresh rate (50 or 60 Hz) can be achieved with only half the amount of data.
An interlaced picture is divided into two halves, the odd and even scan lines. These are “halves” are displayed odd, even, odd, even, etc., at a rate of 60 frames per second. So, in reality at any given time you are only seeing half of the picture (although because the frame rate is so high, your eyes don’t notice it.) Interlaced scanning sometimes results in screen flicker and visible scan lines. Standard analog TV signals are interlaced signals. Progressive scanning takes the whole picture (all scan lines) and displays them at a rate of 30 frames per second. Because the whole frame is reproduced every time, the result is a more solid, film-like picture. Computer monitors use progressive video.
There are basically two ways to display video: interlaced scan or progressive scan. Progressive scan, used in computer monitors and digital televisions, displays all the horizontal lines of a picture at one time as a single frame. Interlaced scan, used in standard television formats (NTSC, PAL, and SECAM), displays only half of the horizontal lines at a time (the first field, containing the odd-numbered lines, is displayed, followed by the second field, containing the even-numbered lines). Interlacing relies on phosphor persistence of the TV tube to blend the fields together over a fraction of a second into a seemingly single picture. The advantage of interlaced video is that a high refresh rate (50 or 60 Hz) can be achieved with only half the bandwidth. The disadvantage is that the vertical resolution is essentially cut in half, and the video is often filtered to avoid flicker (interfield twitter) and other artifacts. It may help to understand the difference by considering how the sou
