Half Empty or half full? Why 768x1024 is HD

rspurgeon

I must amit that I can understand Mr Wards comments about dubious panel resolutions. Lets face it (and im in the market for an HDTV), Why would you spend thousands of pounds on a new HDTV that would then need to scale the broadcast resolution to the native resolution of the panel.

It seems silly that there is a requirement to take one broadcast pixel and fit it into three quarters of a native pixel. Using a mathmatical smoothing algorithm to do this would end up with a resultant picture that looks "out of focus"

The same applies for panels that are higher resolution than the broadcast resolution. Unless both the horizontal and vertical native resolutions are devisable by the broadcast resolution then a smoothing routine would be required to fill one and a half native pixels per broadcast pixel (unless you have blank borders).

In my opinion HDTV should only be HDTV if the native resolution is the same as the broadcast resolution and its one of the following...

1250 X 720
1920 x 1080

ps I understand that there is not really a way to get around scaling between these two resolutions.

I have used LCD laptops for years with native resolution scaling. To be honest ive found the scaling to be unusable and always end up using the panel at native resolution.

It seems pointless buying expensive HDTV panels that end up having to scale. It just ruins what HDTV is all about.

Feel free to knock me down if you disagree, because I still have not decided what technology to invest in.

Kind Regards,

Richard Spurgeon

John C

Nice first post Richard. Welcome to the boards.

It is hard to disagree with your basic assertion that an unscaled picture is better than a scaled one (though I think you'll find the native resolution is 1280x720 rather than 1250). Personally, I think my 1366x768 plasma produces a great picture even if a little voodoo has to happen in the background so the scaling evidentally doesn't bother me.

This is the only line in your post that has any potential for controversy. To say you would only buy a TV that displays a native resolution is one thing; to say that the rest should not even be labeled as HDTV is a far more sweeping comment and one that I would disagree with. As you stated though, that is your opinion and you are entitled to it. Just know that others likely will disagree (myself included).

Again, welcome to the boards and thanks for jumping into the conversation.

zedd

I posted this in a PM but then thought,"what if he dosnt know about PM's ether?" so decided to post it open, it is meant as friendly advice, take it or leave it and welcome to cyberspace or at the very least this little corner of it.

zedd




Hi, a friendly word of advice.

Knowing nothing about you sir i feel compelled to point this out to you.
The last thing you ever want to do on the internet in a chat, room or a boardroom/forum area is to devulge ANY real information about yourself.
If Richard Spurgeon is your real name by posting it out in the open you expose yourself to identity theft.
On the internet you will meet some of the nicest people you will ever meet. Because of the anonimity factor online you have the potential to meet some of the strangest, scariest and at times dangerous people you never wanted to meet.
Please by all means carry on in whatever fashion you are comfortable with but i just thought this sound advice that you may not have thought of.

Regards...Z

__________________

Quote:

Originally Posted by TopperHarley Now I have to be referred to as some kind of loser I also openly admit that I was wrong about the email I thought was from Zedd. I was making fun of him with some buds of mine and they decided it would be funny to play a joke on me. Kinda twisted but we do that kinda stuff to each other all the time. I apologize about that

I have a NERD stalker ROFLMAO

rspurgeon

Thank you for the response John.

Im really looking forward to upgrading to HDTV. Im currently investigating the different types of TV and have decided to go down the Plasma or LCD route. Currently im heading towards Plasma because I believe the contrast ratio is better?

I was going to wait for the 1080i native sets to arrive but since sky is launching shortly, im not sure I will be able to wait.

I was a little OTT about HDTV only being considered HDTV if the resolution stays native because thats unlikely even if its just between 720p and 1080i
Im not sure if this is the right thread to ask this but I do have one question that bugged me for a while.

Its about the difference between interlace and progressive scan. As most HDTV panels (LCD/Plasma) are digital, is it true that the image is always drawn to the panel prgressively?

So an interlaced analog source signal is deinterlaced and digitised and a digital source signal is just progressive anyhow? Therefore surely on a modern Plasma/LCD the only difference is the framerate, which I assume is just half that of a progressive signal at full rate.

So in the digital world the only difference between a 1080i and 1080p is the framerate and this being because DVI was not quick enough?

Sorry for the confusion I have? I understand why we used to have interlace with analog CRT tubes and analog signals, but its confusing when the whole system is digital.

Thanks in advance,

Richard

zedd

Not quite sure what you mean by DVI not being quick enough, as oposed to what?
DVI= Digital Video Interface is the same as HDMI, the plug on HDMI is smaller and shaped different but thats about the only different between the two, DVI and HDMI except that HDMI also carries an audio signal.
The quality of the two vidoe signals between the two should be the same and actually DVI can also carry audio signals as well but has been disfavored for HDMI.
As for speed of transfer (DVI not being quick enough) as long as one is using comparable quality cables digital is digital!

__________________

Quote:

Originally Posted by TopperHarley Now I have to be referred to as some kind of loser I also openly admit that I was wrong about the email I thought was from Zedd. I was making fun of him with some buds of mine and they decided it would be funny to play a joke on me. Kinda twisted but we do that kinda stuff to each other all the time. I apologize about that

I have a NERD stalker ROFLMAO

rspurgeon

Hi Zedd,

What i mean is that DVI / HDMI must have a maximum bitrate currently, and I assumed that it was too slow for 1080p at 60fps?

But ive read a bit more now and it seems the latest DVI / HDMI chips can facilitate the higher bitrate required (assuming good quality cable)?

Im getting excited because the article also says that these new 1080p sets are coming out in april. Maybe I will wait after all.


Kind Regards,

Richard

S0LE_SURVIV0R

You're right sl7vk, Changing his tune a bit.
on the thread
Are Panasonic EDTV'S Good And Is EDTV HD?

Ward Cleaver posted at 02-14-2006, 12:31 PM "

"The resolution on most other 42" EDTV's nowadays is 1024 x 768.

So yes, when compared to the normal 42" EDTV resolution of 1024 x 768, your tv's resolution of 852 x 480 would indeed qualify (and quantify) it as being a "low" definition EDTV...certainly a "lower" definition than the standard 1024 x 768 found on most other 42" EDTV's nowadays.
What you have is a lower tiered, "budget model" EDTV."

See, here is the issue, THE ATSC RATES BROADCAST SIGNALS!
They are not rating TV scalers, not even thinking of that.
It is the Consumer electronics coperation I believe that judges TV's, and agreed that it is the vertical that qulaifies for HD.
I may not have my i dotted on that, but I believe that is what I heard.
http://www.ce.org/shared_files/resou..._Tip_Sheet.pdf

__________________
Sony 40 LCD flat panel XBR &
Panasonic 37 768p Plasma
HD TIVO
The human eye can barely perceive a 1366x768 resolution 10 feet away from a 50 inch
see http://proav.pubdyn.com/2005_January...rallaxview.htm


720p Fastest & Best Temporal Resolution




Sony
"The world's greatest high definition television"

zedd

There are a few sets that can accomidate 1080p on the market current.
The unit i own being one of them.
My monitor is waiting now for tech to catch up to it!

__________________

Quote:

Originally Posted by TopperHarley Now I have to be referred to as some kind of loser I also openly admit that I was wrong about the email I thought was from Zedd. I was making fun of him with some buds of mine and they decided it would be funny to play a joke on me. Kinda twisted but we do that kinda stuff to each other all the time. I apologize about that

I have a NERD stalker ROFLMAO

John C

There is a LOT of heated discussions regarding plasma versus LCD. There are plenty of articles discussing the merits of each so I won't try to write one here. From a practical standpoint I can tell you that most flat panels sales above about 40" are plasma while most below that size are LCD. I think there are 2 major factors at play. First, plasma technology cannot be effective shrunken. Smaller screens = less resolution. Even at 42" screens, most plasma sets cannot display the full resolution of a 720p signal. Second, LCD production cost increases geometrically with screen size. 42" seems to be the point today where people start believing the plasma resolution is good enough while the LCD is a bit too expensive. As you go up in size above that, it becomes a no-brainder to choose plasma for all but the super rich. If you go below that in size, you quickly find LCD is your only option.

Everyone is focusing on 1080p right now. Given the choice, I'd buy a 1080p set over a 720p set also. But since there is no 1080p content available yet, since at my viewing distances I'm not sure how much benefit I'd see, and since the initial sets to support 1080p will likely be pretty pricey, I decided to go ahead and buy a 720p set today instead of wait. That's just my own personal decision though. There are no right or wrong answers, you just have to decide what is right for you.

Technically the answer is usually no, but essentially the answer might be usually yes. To understand the distinction, we have to talk tech for a second. Remember that in old CRT sets (and monitors) a gun was shooting electrons at the screen which caused that spot to glow. That glow would immediately start to fade and the gun needed to "reshoot" or "refresh" that spot over and over again even if it were displaying a static image. In the old living room TV, the gun was literally interlaced, meaning that it only "reshot" every other line with each pass while the other line experienced additional "fade".

With either plasma or LCD technologies, a pixel is either "on" or "off". Unlike a CRT, it doesn't fade. Once turned on, it stays on until turned off. So even though many or even most sets don't de-interlace, the pixels all remain fully bright with no fading making it essentially as if the are repainting the entire screen (though with no motion compensation).

The real key, as was alluded earlier is the motion compensation of the deinterlacing. Just slapping the odd and even lines together is essentially done all the time by virtue of the technology. Blending the picture is a much trickier problem. For that reason, many LCD and plasma TVs will simply throw out either the odd or even half of a 1080i signal and then scale the remaining 520 lines across their resolution. Anyway, the main point is that there is a lot of complexity to all of this. That said, I still think the best test is to go look at sets instead of trying to decipher how all of this is processed within each model.

Nope. The real difference is that the picture was all captured at once so that there is no antimotion magic to be performed within the TV.

No problems. Welcome once again and keep firing away with your questions.

Ward Cleaver

If you purchase any plasma under 50" you will be purchasing an EDTV.

No plasma under 50" is capable of displaying true HD.

Regards,
-Ward

__________________
The ATSC (the body whch sets the standards for HDTV) recognizes only two standards for HDTV...1280 x 720 and 1920 x 1080 www.atsc.org
The ATSC standards for HDTV are recognized by the FCC.

zedd

The above statement beats a dead horse to the point of being pathetic.

A while back i posted a article online that apparently no one bothered reading, below i will post it again.
The article explains the difference beteen EDTV and HDTV; Enjoy


The Difference Between HDTV, EDTV, and SDTV
Evan Powell, ProjectorCentral, October 2, 2003
http://www.projectorcentral.com

The consumer electronics industry has done a spectacular job spreading mass confusion about video. Time was when there was just TV. Now we've got SDTV, EDTV, HDTV, 480i, 480p, 525p, 720p, 1080i, progressive scan, component video, composite video, blah blah blah. Enough to make you feel like you need an engineering degree to buy a projector or TV.



And if you think you are confused now, just go talk to any sales rep on the floor of your local Buster's Big Screen Megastore and you will get some insight into what true confusion is all about. Many of those reps have little training and can't tell you anything meaningful about good video. Invariably however they are pushing the deal of the week and selling equipment that may be exactly wrong for your needs.

Let's talk basics. You want the best picture you can get for your money, right? OK. Getting there is actually easier than you think. Reading the rest of this article will give you most of what you need to sort out the good stuff from the junk.

Our Television/Video System. There are over 250 million televisions in the United States. Almost all of them work exactly the same way. A video signal pumps information into a TV at the rate of 30 frames per second. Each frame is a still picture. But they are displayed so rapidly that they give the appearance of continuous motion, just like an animated cartoon.

Each frame of video contains about 480 active lines of information (482.5 actually, but we will talk round numbers here to communicate the concept). Now a single frame of video is actually painted on the screen line-by-line in two passes. On the first pass, the beam paints all of the odd numbered lines from 1 to 479, top to bottom. That takes 1/60 second. On the second pass it paints all of the even numbered lines from 2 to 480. That also takes 1/60 second. So it takes a total of 1/30 second to display all 480 lines of the frame. This display technique is known as "interlacing."

When they broadcast video information, they need to give CRT-type TVs time to reset the electronic beam to the top of the screen so it can get ready to paint the next sequence of lines. So they build in an interframe gap that equals about 45 lines. There is no picture information in this 45 line gap—it is there just to allow the TV time to get ready to receive the next frame. So the total number of lines in each frame is 480 + 45 = 525. You've probably heard that a TV set has 525 lines. Not so. The signal has 525 lines, but only 480 of them contain active video information that ends up on your screen.

Sometimes you will see this standard analog TV format designated as 525i, which means 525-interlaced. In common usage, a lot of people also use the term "480i" to refer to analog interlaced 480-line active video. However, the industry has recently defined a digital interlaced 480-line format under the array of DTV formats which is known as Standard Definition Television, or SDTV, and 480i is the correct designation for this format.

The Problem with Interlacing: Screen Size

For most of the 50 years that the plain ole "525i" television has been in existence, it has worked just fine. That's because TVs were small. On a 19" TV set the picture looks terrific because the scan lines and the errors introduced by interlacing are too small to see. But as TVs have gotten larger, the scan lines have become more visible.

Not only that, but the interlacing system creates weird "artifacts" when blown up to big-screen proportions. When there is motion in the picture, an object will have moved between the time the first half and the second half of the frame are painted. That makes straight lines break up and look like they've got jagged edges. And on a 60" TV or a genuine really big-screen image from a front projector, the visible scan lines and jaggies are enough to drive you nuts.

If you want a good demo of really bad video, just go into any Buster's Big Screen in your area and look at some of the 60" TVs they have set up. Many of them look terrible—enough to make you want to give up TV altogether. Of course, if you stand back about 30 feet, they look great. But at the distance from which you intend to watch them, you see scan lines, jaggies, and overall picture disintegration that'll make you go blind in a hurry.

The fact is that the 525-line interlaced system we have today was never meant to be blown up to large screen proportions. What works beautifully at 19" is a disaster at 60". And TV designers and marketers know that they couldn't sell really bad video forever just on the WOW factor of the screen size. So they've come up with ways to clean up the picture.

The New Solutions

The single largest step that can be taken toward better big-screen video is to eliminate the interlacing. Interlacing was originally invented to save transmission bandwidth, since with an interlaced signal you only need to send half the frame at a time. But now we have media such as DVD from which we can read and transmit picture information much faster than ever before. So there is no need to stay with an interlaced format.

If we can paint all of the scan lines sequentially from 1, 2, 3…up to 480 on one pass, we can eliminate the jaggies that come from interlacing. This is called "progressive scanning." Note that we don't have any more lines of information—it's still the same 480 lines. But we paint them in sequence from top to bottom. This 480-line progressive scan technique is commonly referred to as 480p. However, there is still the interframe gap, and there are still 525 total lines. So some people call it 525p instead of 480p. But it's the same thing.

Of course the marketers needed to come up with a snazzy name for this marvelous new concept. So they did—Enhanced Definition Television, or EDTV.

EDTV is a major advance

EDTV, or 480p, doesn't sound like much compared to HDTV. But it is in fact a major step forward in picture quality. On a big screen it looks closer in quality to HDTV than it does regular television. And it is here today in its full glory. Most DVD players on the market output both interlaced and progressive signals, and they are getting better and cheaper by the month. So every DVD on the market can be played in EDTV right now!

Now in order to take advantage of 480p, you need two things: (1) a video source such as a DVD player that outputs that signal, and (2) a television or projector that can take that signal as an input. Warning: Most televisions being sold cannot take 480p. Most home theater projectors, even the least expensive ones under $2,000, can.

So here is your first absolute rule for buying a new video display, whether it is a projector or a TV: if you want maximum video quality, make sure to buy a TV or projector that is 480p compatible.

But, you ask, what about regular interlaced video sources like cable television, VCR, laserdisc, and so on—how do I play those signals on a progressive scan video system?

Well, no problem. You simply to feed your new projector or TV the interlaced signal. All progressive scan display systems can take interlaced signals as well. That is because they have a device on board called a deinterlacer or line doubler.

Here is what a line doubler (deinterlacer) does: It takes a 480-line interlaced signal from your cable TV or VCR or laserdisc player or DVD player and recombines the odd and even lines into a sequential 480-line progressive signal. Furthermore, when good line doublers recombine the lines, they look for motion offsets (the jaggies), and make adjustments to smooth them out. So their job is to convert a 525i signal into a much cleaner 480p signal. Some of them do this better than others, but most of them produce a much better signal than they started with.

Furthermore, since the projector/TV scans from top to bottom in 1/60 second, all 480 lines are displayed in that time. So what does the line doubler do with the second 1/60 second, since new frames are arriving at the speed of only 30 frames per second? Simple. It feeds the same 480-line frame to the display a second time.

So, contrary to what you might assume, a line doubler does NOT double the number of lines. Rather it doubles the number of times the 480 lines are painted on the screen during the 1/30 second frame display time. This increases brightness and stability of the image. But most importantly, the elimination or reduction of the jaggies gives you a much cleaner picture.

It used to be that the internal line doublers in projectors and TVs were not very good. They could recombine the lines easily enough, but they weren't capable of smoothing out the motion artifacts. So many folks invested in separate external line doublers that were much more sophisticated. These days internal line doublers are MUCH more comprehensive than they used to be. So the need for an external doubler has diminished. Today, whether you could benefit from investing in an external line doubler or not depends on the quality of the doubler already built into the projector.

So let's forget about HDTV for a moment. The big leap forward that is accessible to everyone right now is EDTV, which is simply progressive scanning. I had friends over recently and I put on the Eagles "Hell Freezes Over" DVD, displaying it on a 120" diagonal screen. They were stunned at the picture quality—"I've never seen ANY big screen ever look that good," said one. "So that's HDTV huh?" Nope. That's just regular DVD my friends, played on a progressive scan DVD player.

Well then, what about HDTV?

The broadcast industry is struggling toward conversion of our system to High Definition Television (HDTV), a conversion which presumably will be complete in another five years. HDTV does two things. First, it increases the number of scan lines on the screen. Second, it widens the aspect ratio of the screen from the standard 4:3 which is what most televisions are today, to 16:9. The wider screen format has a more theatrical look.

The most popular HDTV format is 1080i, or 1080 lines interlaced. As with 525i, the system paints the odd lines first, then the even lines in a second pass. But since there are so many more scan lines, both the lines themselves and the motion jaggies are much less visible.

Nevertheless, the world of videophiles who seek video perfection are looking forward to the day when even this 1080i signal will be presented progressively—1080p. Faroudja is marketing a video processor that will convert 1080i to 1080p, and there are a few very expensive projectors that will handle the scan rates required for this signal. But for those who don't want to spend $30,000 on a big-screen TV just yet, 1080i is the most prevalent format today.

An alternative HDTV format is 720-lines progressive scan, or 720p. Though it has fewer lines, the native progressive scan format eliminates motion artifacts that originate in interlacing, and are still visible in large screen 1080i. So for subject matter that contains a lot of rapid motion--Monday Night Football for example--you can get a clearer, more stable picture from 720p than you can from 1080i. Alternatively, for subject matter that has very little motion, 1080i is capable of rendering more picture detail. Notice that most of the HDTV demo clips being broadcast on HDNet are very slow pans of detailed scenes. They are beautiful images, but those slow pans are intended to disguise the deinterlacing flaws inherent in the 1080i format.

The bottom line is that 1080i and 720p are both very good HDTV formats. One is not better than the other; they are just each better with particular types of subject matter. When done right, both are clearly superior to the NTSC 480-line format we have today.

The funny thing is this. For the videophile who wants to spend a great deal of money to get the best possible picture, HDTV is the solution in theory. But the quality of HDTV signals will be dependent upon a host of variables. And economics will be the primary determinant. One can expect broadcasters to minimize production costs and save bandwidth whenever possible. There is one thing that is certain, and that is that broadcasters have absolutely no interest in boosting the cost of production in order to satisfy the desires of a small contingent of videophiles. They want to spend just enough money make picture quality acceptable to the mass market and no more.

That being the case, don't imagine that HDTV is going to be uniformly as glorious as the pristine demos you might see in well-calibrated retail showrooms. Just as there are variations in picture quality today between channels, and between programs on given channels, so will the quality of production HDTV vary as well.

Meanwhile, the quality of the 480-line system continues to improve. Video decoders, deinterlacers, and scalers have all gotten much better at a rapid pace. The video transfer quality on DVDs has improved even since DVDs were introduced. So even without HDTV, large screen projectors today look amazingly good compared to similar products released just 18 months ago. On occasion we see DVD material that is superior to some of the broadcast HDTV we are getting. So the fact is that for the mass consumer market there is not a great deal of difference between HDTV and today's new 480p when it is done right. The quality difference is certainly nothing that the majority of the population would want to pay much extra for.

So the bottom line is this--don't worry about HDTV for now. It will continue to evolve over the next few years and it will be whatever it will be. Who cares? The unfortunate thing is that people are sitting on the sidelines waiting for HDTV to get serious, and they are missing out on EDTV, which is the biggest advance in video quality since color TV.

The real reason to step up to the latest video systems is not HDTV, but EDTV, or more simply 480p. If you are buying for home theater, get a projector or big-screen that handles 480p as well as 1080i and 720p. If a projector or TV takes 480p it will probably take 1080i and 720p as well. But that won't be its major benefit since there is not a huge amount of HDTV source material at hand. But today every DVD on the market can be played in EDTV.

Once you've got the fundamentals of 480p installed, then just sit back and enjoy your new vastly improved video system. Once you experience the quality of today's EDTV, you may find yourself thinking that you don't care quite as much about HDTV as you once did.





Source:
ProjectorCentral

__________________

Quote:

Originally Posted by TopperHarley Now I have to be referred to as some kind of loser I also openly admit that I was wrong about the email I thought was from Zedd. I was making fun of him with some buds of mine and they decided it would be funny to play a joke on me. Kinda twisted but we do that kinda stuff to each other all the time. I apologize about that

I have a NERD stalker ROFLMAO

S0LE_SURVIV0R

Zedd no matter how many people try to tell him. .... he's just a guy who is not going to admit he was wrong. I work with a guy like that to.
So he wants to call 768x1024 plasmas EDTV, let him live in his own world, just making a fool of himself.

__________________
Sony 40 LCD flat panel XBR &
Panasonic 37 768p Plasma
HD TIVO
The human eye can barely perceive a 1366x768 resolution 10 feet away from a 50 inch
see http://proav.pubdyn.com/2005_January...rallaxview.htm


720p Fastest & Best Temporal Resolution




Sony
"The world's greatest high definition television"

Ward Cleaver

No plasma under 50" is capable of displaying true HD.

Regards,
-Ward

__________________
The ATSC (the body whch sets the standards for HDTV) recognizes only two standards for HDTV...1280 x 720 and 1920 x 1080 www.atsc.org
The ATSC standards for HDTV are recognized by the FCC.

sl7vk

PCMag called your TV a 4000 dollar paperweight.

Regards,
-Thomas

__________________
"Their LCD tv's are also assembled in the Netherlands...Belgium to be exact."
-Ward Cleaver

S0LE_SURVIV0R

Ward you are insane in my opinion, calling 768p sets EDTV's. Go get some help along with the people who believe the Earth is flat.

__________________
Sony 40 LCD flat panel XBR &
Panasonic 37 768p Plasma
HD TIVO
The human eye can barely perceive a 1366x768 resolution 10 feet away from a 50 inch
see http://proav.pubdyn.com/2005_January...rallaxview.htm


720p Fastest & Best Temporal Resolution




Sony
"The world's greatest high definition television"