Understanding the distinction between progressive video and interlace video is key to understanding high definition. Interlace format is naturally the basic format behind normal TV image. Half of the resolution is virtual, it doesn’t exist. This works by splitting every frame into 2 fields. on the first line is every other line of data. So, every even line of resolution is on the TV. And every odd line of resolution is not on the screen its black. The second field reverses this, so that every odd line has the actual data on it & every even line is dark on the screen. When you combine those 2 fields you get one frame & they flash back & forth very quickly. What this means, is that any moment in time you don’t have the full resolution offered to you. You’ve only got half the resolution on the screen. The flash is so quick that the human eye cant pick it up.
What it does do is make something called interlace-artifacting. Interlace-artifacting is when you take something like a soccer ball and you kick it fast across the screen. What ends up happening is it smears and smudges, you get weird lines that break through the ball, because the set cant keep up and even if it did, 50% of the information is virtual. The human-eye can grasp these changes. This means that its also near impossible to put interlace things on a progressive computer screen. Most H.D. screens are progressive. Your plasma screen is progressive; your LCD screens are progressive; Also DLP screens are progressive. The only thing that’s left is CLT monitors.
So whats progressive? Opposed to what we talked about earlier, Progressive H.D. is when all lines are on the TV at the same time. This means no virtual field, everything is a full frame. That means when you kick that soccer ball across the field. Both lines have information, as opposed to Interlace where its every other one. There is no interlace-artifacting that has smear on it, none of that. So the picture is pure & perfect every single time. When you go watch a movie in the cinema, that’s progressive. This makes progressive hands down better than interlacing.
There are two different resolutions in HD video, 720 and 1080. Interlace and progressive goes after that, this means that something like 720 would mean 720 lines of resolution. This means its always there as opposed to every other one. 1080 equals 1080 virtual lines of resolution. So 540 actual lines of resolution. A lot of people think that 1080i is a standard above 720p, nevertheless because of that virtual data its not. The best high definition format is 1080p then 720p then 1080i. 1080p being 1080 progressive lines of resolution or all of the lines out there.
HD Blue-Ray’s can handle 1080p. Youtube is now 1080p combatable, but you cannot broadcast 1080p, at least not today. The highest broadcast lines of resolution you can go 1080 interlace lines or 720 progressive lines. If you have a choice, I highly recommend doing 720p before 1080i. Especially if you have a plasma monitor, a DLP monitor or a LCD monitor, because your display technology is not interlace its progressive.
There’s one more number that comes into the formula & that’s the frame rate. If you want to be aware of the frame rate then its crutial that you understand the differences between progressive and interlace. Interlace means 2 fields make one frame. So this means that the measure not by frames, but by fields. So lets use 1080i vs. 1080p for example. Every once in awhile you will see 1080/60. That means 1,080 interlace lines at 60 frames/sec. Interlacing may get you every time. It gets you on interlacing artifacting and on frame rate. 1080i/60 is actually only 1080/30 & it have a lot of extra interlace garbage that goes with it.
So lets go over the actual HD spectrum again. It starts at 1080i then 720p then at best at 1080p. Some people may say. “well what about 480p”? 480 Is not H.D.. Its considered to be called “enhanced definition. At the end of the day every person has there own opinions as to the order they go in, but all can agree that 1080p is the winner.
So those are your H.D. formats. Hopefully you’ll now know which works best for your situation.