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Official "1080p Vs. 720p" Thread Discussion - Page 43

post #1261 of 1457
Thanks, I know I come off like a jerk, but I'm not the kind of guy to follow a status quo. if you put on TNT, watch Law and Order, focus on one thing, look at the color, gloss, switch over to 720 remember that object. That object doesn't look better in 720? Pause the image and do it. Turn off native, pick only 720 and 1080i and toggle back and forth concentrating on the object.
post #1262 of 1457
Quote:
Originally Posted by mailiang View Post

If you're not getting close to Blu-Ray quality on stations like AMC HD, TNT HD, Showtime and Starz, with the box set to native, then it's 'we have a problem Houston!'


Ian

I think these sort of statements cause problems, as it is matter of opinion. From my eyes, there is nothing on broadcast or satellite TV that comes even close to Blu-Ray. I see artifacts and issues with all channels and they cannot compete to the nice, clean picture of Blu-Ray.
post #1263 of 1457
Quote:
Originally Posted by mailiang View Post

Blu-Ray is a progressive format.

Interlaced is also used on Blu-ray - at least in 2D.
post #1264 of 1457
Quote:
Originally Posted by Sole_Survivor View Post

Thanks, I know I come off like a jerk, but I'm not the kind of guy to follow a status quo. if you put on TNT, watch Law and Order, focus on one thing, look at the color, gloss, switch over to 720 remember that object. That object doesn't look better in 720? Pause the image and do it. Turn off native, pick only 720 and 1080i and toggle back and forth concentrating on the object.

I have, and my system in native looks much cleaner. I wish I had a answer, but like I posted earlier, if your set up is scaling better at 720p only, then fine.

Quote:
Originally Posted by primetimeguy View Post

I think these sort of statements cause problems, as it is matter of opinion. From my eyes, there is nothing on broadcast or satellite TV that comes even close to Blu-Ray. I see artifacts and issues with all channels and they cannot compete to the nice, clean picture of Blu-Ray.

I said close. But no cigar. Not all Blu-Ray is created equal and there can be issues with their content as well.

Quote:
Originally Posted by Joe Bloggs View Post

Interlaced is also used on Blu-ray - at least in 2D.

Sorry, I was referring to HDMI, which I assume Sole_Survivor was using on his HDTV.


Ian
post #1265 of 1457
Quote:
Originally Posted by mailiang View Post


I said close. But no cigar. Not all Blu-Ray is created equal and there can be issues with their content as well.

Sorry, I was referring to HDMI, which I assume Sole_Survivor was using on his HDTV.

Ian

True, not all transfers are equal, but still not even close to me.

I don't understand your progressive/Blu-ray/hdmi comment. Some Blu-rays are 1080i native, doesn't matter what u r using for a connection.
post #1266 of 1457
Quote:
Originally Posted by mailiang View Post

Sorry, I was referring to HDMI, which I assume Sole_Survivor was using on his HDTV.

HDMI can send interlaced as well as progressive.
post #1267 of 1457
Quote:
Originally Posted by primetimeguy View Post

True, not all transfers are equal, but still not even close to me.

Who's your service provider?

Quote:
I don't understand your progressive/Blu-ray/hdmi comment. Some Blu-rays are 1080i native, doesn't matter what u r using for a connection.

Maybe so, but I watch a lot of BD's and I personally never came across one.


Ian
post #1268 of 1457
Quote:
Originally Posted by Joe Bloggs View Post

HDMI can send interlaced as well as progressive.


I realize that. But most BD's offer up to 1080p through the HDMI input which I assumed was the format Sole was using, since he has a progressive HDTV. Thanks.


Ian
post #1269 of 1457
Quote:
Originally Posted by mailiang View Post

Who's your service provider?



Maybe so, but I watch a lot of BD's and I personally never came across one.


Ian

Dishnetwork and antenna. Dish even has 1080p VOD that is not transmitted via satellite, rather it is predownloaded via broadband and therefore can have higher bitrates than typical broadcast. While it is an improvement, I still see compression artifacts in high action scenes. I guess I'm one of those people that notice all the issues and I will say I don't recall the last time I watched a broadcast channel and said WOW. Put in a Blu-Ray and I do.


I watch a lot of live concerts on Blu-Ray and those tend to be 1080i.
post #1270 of 1457
Quote:
Originally Posted by primetimeguy View Post

Dishnetwork and antenna. Dish even has 1080p VOD that is not transmitted via satellite, rather it is predownloaded via broadband and therefore can have higher bitrates than typical broadcast. While it is an improvement, I still see compression artifacts in high action scenes. I guess I'm one of those people that notice all the issues and I will say I don't recall the last time I watched a broadcast channel and said WOW. Put in a Blu-Ray and I do.


I watch a lot of live concerts on Blu-Ray and those tend to be 1080i.

With the end of CD's I might be doing the same thing eventually. I use to have Dish, but I switched to DTV and I find that many of their satellite stations like the ones I've mentioned, offer better picture and sound quality. AMC's Hells On Wheels and Starz's Strike Force offer PQ about as close as you can get to BD. They rival PPV which is now broadcast in 1080p. They also offer broadband VOD, but I've never used it.


Ian
post #1271 of 1457
Quote:
Originally Posted by Joe Bloggs View Post

Yes, I was just trying to point out that at the same source fps, interlaced would have double the temporal resolution.

Better yes but not double, and that is not the same as motion resolution. If it's that easy than progressive 1080p is useless.

Quote:
Originally Posted by Joe Bloggs View Post

Yes, I know it won't be as good/accurate/as true resolution per motion sample (which is why I think we should have 1080p50/60 instead). But couldn't that be sort of how some consumer camcorders/cameras currently achieve high fps (eg. 200-1000 fps) for slow motion?
eg. recording 240 fps at 448x336 or 600 fps at 192x108

A bit like interlacing, but instead using different pixels in the sensor for different temporal samples, a bit like this:

http://www.technomaly.com/2010/02/18...h-speed-video/

Like all things in life, it's a compromise. You can't get something for nothing. You can marginalise quality for speed up to a point of visual perception. Similarly interlacing compromises quality. Video capture is not just about fps or resolution though that is what we are discussing here. It is also about CCD/CMOS sensor, optics, processor, speed/bandwidth, post production etc. You can get more insights in the blu ray threads.

But we always have to keep certain variables constant to have a meaningful discussion. So if we assume the transports and fps are constant then progressive is almost ALWAYS better than interlace. That's why again, comparing different stations or TV is interesting anecdotal but frankly not conclusive.

Quote:
Originally Posted by Joe Bloggs View Post

I was talking mostly about motion quality - smoothness of motion - and we have no broadcast-to-home/Blu-ray 1080p50/60 sources yet, so interlaced is the better currently delivered format for motion smoothness/realism (or 720p50/60...).

The Olympics will also have some events shot at 7680x4320p60 which is a better format (not to consumers homes though).

The BBC is already broadcasting where they are broadcasting (in the UK anyway) in a sort of 1080p25 mode or 1080/50i depending on the GOP (I think it's all within 1080/50i because that's how some set top boxes identify it, but some parts must be flagged as 1080p25 somehow). Obviously when the GOP is 1080/50i that will be the one with twice as good motion quality (motion smoothness). And when it's jerky/stroby/unrealistic motion, that will be the 1080p25 mode. So having an added mode for unrealistic/jerky/stroby motion doesn't seem very advanced to me, especially if it could make mistakes or due to only being allowed to switch once per GOP, switch to that mode on content that is 50hz. You mention the Olympics - I doubt they would want the 1080p25 mode for the actual live events - it being half as good for motion quality/realism as the 50i mode.

One thing we certainly agree is that higher fps is better for motion "smoothness". But like I said, whether 1080i60 is better or 720p60 is better for Picture Quality has been debated to death in many forums. IMHO one thing certain is that 1080p50/60 broadcast will end these arguments

4K broadcast in Olympics has been discussed in the 4k thread. They may also have 3D broadcast though it is not confirmed yet.

I think you are confusing the mechanics between 1080p25 and 1080i50 (or 1080i/25 under another convention). Both ARE 25fps. FPTV nowadays are all progessive displays. The reason why 1080i50 looks smoother in motion is because it tricks the eye into seeing higher fps with more interlaced content but in both cases the TV is refreshing at 25Hz. You get to choose PQ 1080p25 or motion smoothness 1080i50.

Quote:
Originally Posted by mailiang View Post

I realize that. But most BD's offer up to 1080p through the HDMI input which I assumed was the format Sole was using, since he has a progressive HDTV. Thanks.


Ian

Actually the older BDs were interlaced and the older FPTV only accept interlaced signals, progressive source like 1080p24 is RELATIVELY new. Like I said, we LIVED in a CRT interlaced world, but it's time to move on.

Quote:
Originally Posted by Sole_Survivor View Post

Well, I restfully disagree with point 4 of that list. It appears to be that that way, common sense wise but it is not the result I am getting.

In reality that's how your EBU test is also configured ie to keep the source constant except to scale & interlace. Even BD VC-1 and AVC is not lossless (hence the "faith" in bit rates as a quality reference) so technically there is a difference between 1080i and 1080p even for blu ray. (I'm not sure however whether is it perceptible or not in reality if your source is constant ie lossless vs lossy as it's a function of visual acuity.) Any lossy intermediate manipulation of source will degrade the quality.
post #1272 of 1457
Quote:
Originally Posted by Joe Bloggs View Post

Yes, I was just trying to point out that at the same source fps, interlaced would have double the temporal resolution.

Quote:
Originally Posted by specuvestor View Post

Better yes but not double,

Yes, double. 50i where each field is from a different point in time is double the temporal resolution as 25p (when played back - 50Hz instead of 25Hz - see below).
Quote:
I think you are confusing the mechanics between 1080p25 and 1080i50 (or 1080i/25 under another convention). Both ARE 25fps. FPTV nowadays are all progessive displays. The reason why 1080i50 looks smoother in motion is because it tricks the eye into seeing higher fps with more interlaced content but in both cases the TV is refreshing at 25Hz.

No, a good, progressive display would de-interlace 50i content where each field is from a different point in time to 50 fps. See de-interlacing in wikipedia. I think the minimum refresh rate of an LCD TV is 50Hz? Maybe 48Hz for Plasma (for 24Hz content)?

Quote:
4K broadcast in Olympics has been discussed in the 4k thread.

They'll be transmitting almost 4x the pixels as 4K - ie. they will be sending 7680x4320 - which is nearer to 8K than 4K.
post #1273 of 1457
Quote:
Originally Posted by specuvestor View Post

Actually the older BDs were interlaced and the older FPTV only accept interlaced signals, progressive source like 1080p24 is RELATIVELY new.

Relatively new? BD ain't that old to begin with!

Quote:
Originally Posted by specuvestor View Post

Like I said, we LIVED in a CRT interlaced world, but it's time to move on.

I'll drink to that!



Cheers!


Ian
post #1274 of 1457
Quote:
Originally Posted by Joe Bloggs View Post

Yes, double. 50i where each field is from a different point in time is double the temporal resolution as 25p (when played back - 50Hz instead of 25Hz - see below).

No, a good, progressive display would de-interlace 50i content where each field is from a different point in time to 50 fps. See de-interlacing in wikipedia. I think the minimum refresh rate of an LCD TV is 50Hz? Maybe 48Hz for Plasma (for 24Hz content)?


They'll be transmitting almost 4x the pixels as 4K - ie. they will be sending 7680x4320 - which is nearer to 8K than 4K.

IIRC your temporal resolution cannot be doubled as the eye is tricked by retina persistence on interlaced image. Temporal resolution is better than 720p but not doubled, while motion resolution suffers. Correct me if I'm wrong with link. Here's an old article which is still somewhat relevant on the illustrations about 1080i capture (but IMHO some caveats for eg the deinterlacing algo and the TV native resolution and source, and technology has advanced since then):
http://www.hometheaterhifi.com/techn...concerned.html

And this is from wikipedia that you reference me to (which I didn't look originally):

"Weaving is done by adding consecutive fields together. This is fine when the image hasn't changed between fields, but any change will result in artifacts known as "combing," when the pixels in one frame do not line up with the pixels in the other, forming a jagged edge. This technique retains the full vertical resolution at the expense of half the temporal resolution (motion)."
"Line doubling takes the lines of each interlaced field (consisting of only even or odd lines) and doubles them, filling the entire frame. This results in the video having a frame rate identical to the field rate, but each frame having half the vertical resolution, or resolution equal to that of each field that the frame was made from."

Weaving I think is the most common which will collapse 50i to 25fps. It looks smoother because there is more information in interlaced but less resolution than 1080p. On the other hand techniques like line doubling will keep 50i at 50fps. Either way it will have artifacts not evident by progressive capture.

ALL modern FPTV will deinterlace any interlaced source. It can be displaying in 50Hz in PAL and 60Hz in NTSC in a "classical" sense but it is not the minimum. 50/60Hz was a convenient electronic assimilation to the local electricity Hz for CRT. In modern displays there are no such constraints so it can be frequency matched to native frame rates like 24Hz for 24fps but pulldowns from 2:2 to 4:4 are implemented for plasma to prevent flickers. LCD however need MCFI since pulldowns are ineffective as they are sample and hold displays, so they have to go upto 120Hz and more with backlight scanning. Common misconception for LCD owners is to mistake retina persistence blur to source artifacts.

Thanks for correction on Olympic "Super Hi Vision". I had assumed wrongly that they are referring to 4k without looking at the spec properly. Not only are these not for consumers but also they are only broadcast in specific locations.
http://www.avsforum.com/avs-vb/showt...6#post21218326
post #1275 of 1457
Quote:
Originally Posted by Joe Bloggs View Post

Yes, double. 50i where each field is from a different point in time is double the temporal resolution as 25p (when played back - 50Hz instead of 25Hz - see below).

No, a good, progressive display would de-interlace 50i content where each field is from a different point in time to 50 fps. See de-interlacing in wikipedia. I think the minimum refresh rate of an LCD TV is 50Hz? Maybe 48Hz for Plasma (for 24Hz content)?


They'll be transmitting almost 4x the pixels as 4K - ie. they will be sending 7680x4320 - which is nearer to 8K than 4K.

Quote:
Originally Posted by specuvestor View Post

IIRC your temporal resolution cannot be doubled as the eye is tricked by retina persistence on interlaced image. Temporal resolution is better than 720p but not doubled, while motion resolution suffers. Correct me if I'm wrong with link. Here's an old article which is still somewhat relevant on the illustrations about 1080i capture (but IMHO some caveats for eg the deinterlacing algo and the TV native resolution and source, and technology has advanced since then):
http://www.hometheaterhifi.com/techn...concerned.html

And this is from wikipedia that you reference me to (which I didn't look originally):

"Weaving is done by adding consecutive fields together. This is fine when the image hasn't changed between fields, but any change will result in artifacts known as "combing," when the pixels in one frame do not line up with the pixels in the other, forming a jagged edge. This technique retains the full vertical resolution at the expense of half the temporal resolution (motion)."
"Line doubling takes the lines of each interlaced field (consisting of only even or odd lines) and doubles them, filling the entire frame. This results in the video having a frame rate identical to the field rate, but each frame having half the vertical resolution, or resolution equal to that of each field that the frame was made from."

Weaving I think is the most common which will collapse 50i to 25fps. It looks smoother because there is more information in interlaced but less resolution than 1080p. On the other hand techniques like line doubling will keep 50i at 50fps. Either way it will have artifacts not evident by progressive capture.

ALL modern FPTV will deinterlace any interlaced source. It can be displaying in 50Hz in PAL and 60Hz in NTSC in a "classical" sense but it is not the minimum. 50/60Hz was a convenient electronic assimilation to the local electricity Hz for CRT. In modern displays there are no such constraints so it can be frequency matched to native frame rates like 24Hz for 24fps but pulldowns from 2:2 to 4:4 are implemented for plasma to prevent flickers. LCD however need MCFI since pulldowns are ineffective as they are sample and hold displays, so they have to go upto 120Hz and more with backlight scanning. Common misconception for LCD owners is to mistake retina persistence blur to source artifacts.

Thanks for correction on Olympic "Super Hi Vision". I had assumed wrongly that they are referring to 4k without looking at the spec properly. Not only are these not for consumers but also they are only broadcast in specific locations.
http://www.avsforum.com/avs-vb/showt...6#post21218326


Would you guys or as they say in the UK, mates, like a room?


Ian
post #1276 of 1457
Quote:
Originally Posted by specuvestor View Post

IIRC your temporal resolution cannot be doubled as the eye is tricked by retina persistence on interlaced image.

But you aren't seeing an interlaced image when you are viewing a progressive display (LCD or Plasma) that has de-interlaced the interlaced content to a progressive format (eg. 50p).
Quote:


Temporal resolution is better than 720p but not doubled, while motion resolution suffers.

I'm saying temporal resolution of 50i can be (if shot how I mentioned) twice as good as 25p, but the same temporal resolution as 720p50 (ie. assuming the de-interlacing is done correctly - and it might not always be - 50i and 720p50 will/should both show 50 different images per second on the display - so the temporal resolution would be the same.
Quote:


Correct me if I'm wrong with link. Here's an old article which is still somewhat relevant on the illustrations about 1080i capture (but IMHO some caveats for eg the deinterlacing algo and the TV native resolution and source, and technology has advanced since then):
http://www.hometheaterhifi.com/techn...concerned.html

I haven't read it totally, but it looks about right when it gets to talking about de-interlacing.
Quote:


And this is from wikipedia that you reference me to (which I didn't look originally):

"Weaving is done by adding consecutive fields together. This is fine when the image hasn't changed between fields, but any change will result in artifacts known as "combing," when the pixels in one frame do not line up with the pixels in the other, forming a jagged edge.

Yes, that's why a good de-interlacer would only use weaving on parts of the frame that are not in motion.
Quote:


This technique retains the full vertical resolution at the expense of half the temporal resolution (motion)."

- yes so the bits of the frame that only move 25 times a second or are stationary (or 25p footage within 50i) can de-interlaced and (in theory, and if done correctly, and if not filtered) be just as good as 25p.
Quote:


"Line doubling takes the lines of each interlaced field (consisting of only even or odd lines) and doubles them, filling the entire frame. This results in the video having a frame rate identical to the field rate, but each frame having half the vertical resolution, or resolution equal to that of each field that the frame was made from."

Yes, that's why the better de-interlacers would use a combination of the two (weaving + line doubling)- or motion compensation etc.
Quote:


Weaving I think is the most common which will collapse 50i to 25fps. It looks smoother

Just weaving would only (or should only) be done for 50i content if the content was shot in 25p (25Hz) mode. eg. the latest Doctor Who/Merlin etc. - stuff that was shot with a 'film look'. This won't be as smooth - the motion will be half as smooth as content shot in 50i (50hz) mode. That's why there's more judder in a fight sequence in Merlin, but live football looks okay. They wouldn't use 25p mode for live football or live events at the Olympics because it would be too juddery (too low temporal resolution).
Quote:


ALL modern FPTV will deinterlace any interlaced source.

True, which is why your statement "the eye is tricked by retina persistence on interlaced image" doesn't apply when viewing on modern flat panel displays.
Quote:


Thanks for correction on Olympic "Super Hi Vision". I had assumed wrongly that they are referring to 4k without looking at the spec properly. Not only are these not for consumers but also they are only broadcast in specific locations.

True. They are broadcast to a few public displays only (3 in the UK and a few in other countries), not to any consumer TVs.
post #1277 of 1457
ok let me guess... you belong to those group that believe that deinterlacing can be done PERFECTLY? If so then I can understand why you are not getting me

We had a discussion on another thread (in my previous links) that I had argued deinterlacing cannot be perfect. Think of it this way: If it can then progressive format is useless. Why bother with 1080p broadcast and spend capex to change to progressive equipments? Might as well have 1080i48 as BD standard? Or move forward with 1080i120 instead of 1080p60.

Motion compensated deinterlacing is as good as MCFI. But if you like the soap opera effect then maybe it is not an issue to you. Interlacing cannot be as good as progressive, if you disagree on this then we just have to agree to disagree

If you're talking about 25p or 24p vs 50Hz then like I said there is no argument with respect to "smoothness". Higher fps is better for motion. Period. But 50i as psuedo-50fps (with appropriate technique) is just a stop gap measure. It's similar to why some find classical 2:3 pulldown as "smoother" than 24p. But they are imperfections created due to hardware and bandwidth limits. It is a TECHNIQUE but not what we want to achieve as an end.

Do understand smoothness and PQ are TWO different thinigs CURRENTLY. That's what makes 720p60 and 1080i60 arguments so debatable. With 1080p60 it will be optimal.

Quote:
Originally Posted by Joe Bloggs View Post

But you aren't seeing an interlaced image when you are viewing a progressive display (LCD or Plasma) that has de-interlaced the interlaced content to a progressive format (eg. 50p).

True, which is why your statement "the eye is tricked by retina persistence on interlaced image" doesn't apply when viewing on modern flat panel displays.

You ARE seeing interlacing on a progessive picture when you weave them... THAT's the artifact. So they try to remove combing artifact by line doubling or blending, but introducing other artifacts. Subtle combing may not be easily perceivable which, and as per my previous point 6, also depends on the size of your display and your sitting distance as well.

The brain is tricked by retina persistence from the interlacing lines in a progressive image displayed that it appears as somewhat sigular image. This is the BASIC concept behind CRT interlacing that you see ONE image even though it is only half image dispalyed every 1/60 second. But this trick breaks down on high motion because combing will be much more obvious, but it will appear "smoother" than a low fps content. When you PAUSE the content sometimes you'll see the deinterlaced image and the combing artifact.
post #1278 of 1457
Quote:
Originally Posted by specuvestor View Post

ok let me guess... you belong to those group that believe that deinterlacing can be done PERFECTLY?

Of course not, I'd much rather have good 1080p50 than 1080/50i, and 1080p60 than 1080/60i. With interlacing (other than 24/25/30p in an interlaced signal) they don't even let the encoder know about half the lines in each field, so they have to guess/estimate/make assumptions about what pixels were in the missing lines or line double the parts it thinks are in motion etc..

Quote:


Interlacing cannot be as good as progressive

I'm saying it depends for motion realism - it can be better than the progressive they are currently giving us with broadcasts/Blu-ray (eg. 1080p24/1080p25/1080p30).

I've just been saying that current 1080i is better than the current 1080p that we get now from broadcasters/Blu-ray for realistic motion. Of course when they give us 1080p50/60 at appropriate bitrates, that will no longer be the case.
Quote:


You ARE seeing interlacing on a progessive picture when you weave them... THAT's the artifact.

Which they shouldn't be doing. If you're seeing that type of artefact, they've de-interlaced that bit incorrectly (though as has been said, it's not possible to de-interlace totally correctly)
Quote:


So they try to remove combing artifact by line doubling or blending, but introducing other artifacts. Subtle combing may not be easily perceivable which, and as per my previous point 6, also depends on the size of your display and your sitting distance as well.

Yes, they'll use combinations of them/motion compensation. But yes, it still won't be perfect.
Quote:


The brain is tricked by retina persistence from the interlacing lines in a progressive image displayed that it appears as somewhat sigular image. This is the BASIC concept behind CRT interlacing that you see ONE image even though it is only half image dispalyed every 1/60 second. But this trick breaks down on high motion becuase combing will be much more obvious, but it will appear "smoother" than a low fps content. When you PAUSE the content sometimes you'll see the deinterlaced image and the combing artifact.

Again CRT is different. LCD/Plasma both de-interlace to progressive - totally different method than is used by CRT.
If you pause the content and you're using a Blu-ray player playing interlaced footage and see a combing artefact, it could be using the wrong method (or maybe it's just the way the pause mode works on it, and it doesn't show it like that on normal playback). On some players there's Film mode/Video mode/auto for when it's playing interlaced content (and you could get combing artefacts if you've selected the wrong one). Some can also pause on fields and not just frames.
post #1279 of 1457
I can get a great deal on a space for a debate. It even has a black board





Ian
post #1280 of 1457
^^ A good, civil and grounded debate is what this forum is about

Quote:
Originally Posted by Joe Bloggs View Post

Of course not, I'd much rather have good 1080p50 than 1080/50i, and 1080p60 than 1080/60i. With interlacing (other than 24/25/30p in an interlaced signal) they don't even let the encoder know about half the lines in each field, so they have to guess/estimate/make assumptions about what pixels were in the missing lines or line double the parts it thinks are in motion etc..


I'm saying it depends for motion realism - it can be better than the progressive they are currently giving us with broadcasts/Blu-ray (eg. 1080p24/1080p25/1080p30).

I've just been saying that current 1080i is better than the current 1080p that we get now from broadcasters/Blu-ray for realistic motion. Of course when they give us 1080p50/60 at appropriate bitrates, that will no longer be the case.

Which they shouldn't be doing. If you're seeing that type of artefact, they've de-interlaced that bit incorrectly (though as has been said, it's not possible to de-interlace totally correctly)

Yes, they'll use combinations of them/motion compensation. But yes, it still won't be perfect.

Again CRT is different. LCD/Plasma both de-interlace to progressive - totally different method than is used by CRT.
If you pause the content and you're using a Blu-ray player playing interlaced footage and see a combing artefact, it could be using the wrong method (or maybe it's just the way the pause mode works on it, and it doesn't show it like that on normal playback). On some players there's Film mode/Video mode/auto for when it's playing interlaced content (and you could get combing artefacts if you've selected the wrong one). Some can also pause on fields and not just frames.

If you are saying based on CURRENT available format, pseudo 50/60Hz interlaced content is better for motion perception, then we have already been in agreement. PQ wise however is another issue altogether.

CRT & FPTV are of course different. The principles behind retina persistence remain the same as our eyes are not different They're a major contributor to LCD motion blur.

The topic is about broadcast and combing effect is evident for interlace. Even for blu ray format which is much less evident (as it limits the number of nodes in the value chain that can manipulate the content) there are videophiles that complains about it. You can check out the Planet Earth Blu ray discussion even though it was captured native 1080i50, vs 24p deinterlaced in US. And like you said it depends on the equipment that you use for the deinterlacing as well. Progressive source will take away this hardware requirement.

Nonetheless I think it is much less a concern for blu ray unless one is very videophile. Not so for broadcast though, which is the theme of this discussion. The artifacts are effectively what the OP experienced:
Quote:
Originally Posted by Sole_Survivor View Post

I'll bet anyone any amount of money show me any 1080i channel on directv in 1080i and switch it to 720 I'll tell the difference 10 times out of 10, 100 out of 100. I did this with 3 sets and 3 different boxes for months. I know what that 720p conversion looks like on Directv. I'm not looking too much into. I presented enough articles to point out 1080i's artifacts and a facts that 1080i is more like 1035 x 1440. As well as official tests by the EBU that gave the 720 signal a clear win over 1080i.
post #1281 of 1457
Quote:
Originally Posted by specuvestor View Post

A good, civil and grounded debate is what this forum is about

I'm calling you professor specuvester from now on.


Quote:
Originally Posted by specuvestor View Post

Nonetheless I think it is much less a concern for blu ray unless one is very videophile. Not so for broadcast though, which is the theme of this discussion. The artifacts are effectively what the OP experienced

I agree, but as we discussed, these artifacts are probably the result of issues which probably have less to do with DTV in general, and more to do with his system set up.



Ian
post #1282 of 1457
Professor? Not good as there are many more knowledgeable people in this forum. I only know big picture, not so much on details

Artifacts on OP is likely due to multiple factors including 1080i/720p perception difference. As usual unless one has controlled environment like EBU it is hard to conclude which factor is overriding. And even so no controlled environment can be totally "objective" in the real world.
post #1283 of 1457
Quote:
Originally Posted by specuvestor View Post

Professor? Not good as there are many more knowledgeable people in this forum. I only know big picture, not so much on details

Artifacts on OP is likely due to multiple factors including 1080i/720p perception difference. As usual unless one has controlled environment like EBU it is hard to conclude which factor is overriding. And even so no controlled environment can be totally "objective" in the real world.


Not so much on details, professor?


Ian
post #1284 of 1457
Despite all the facts with links, and tests results I presented in this thred, like a religion, people stuck up for 1080 interlaced. Here is a link (another one) that proves 720p is better. I claim victory not only with the official test by the EBU in my signature, but read this.

"The advocates of 1080i HDTV support their cause with a flurry of numbers: 1080 lines, 1920 pixels per line, 2 million pixels per frame. The numbers, however, don't tell the whole story. If we multiply 1920 pixels per line times 1080 lines, we find that each 1080i frame is composed of about two million pixels. 1080i advocates are quick to point out that a 720P frame, at 1280 pixels by 720 lines, is composed of about one million pixels. They usually fail to mention that during the time that 1080i has constructed a single frame of two million pixels, about 1/30 second, 720P has constructed two complete frames, which is also about two million pixels. Thus, in a given one-second interval, both 1080i and 720P scan out about 60 million pixels. The truth is that, by design, the data rates of the two scanning formats are approximately equal, and 1080i has no genuine advantage in the pixel rate department. In fact, if the horizontal pixel count of 1080i is reduced to 1440, as is done in some encoders to reduce the volume of artifacts generated when compressing 1080i, the 1080i pixel count per second is less than that of 720P.

Another parameter 1080i advocates use to advance their cause is resolution. Resolution is the ability to preserve the separate components of fine detail in a picture, so that they may be discerned by the viewer. But picture quality is not dependent on resolution alone. Numerous studies of perceived picture quality reveal that it is dependent on brightness, color reproduction, contrast, and resolution. Color reproduction is identical in all HDTV scanning formats, and may thus be disregarded as a factor. A typical study assigns the following weights to brightness, contrast, and resolution:

Contrast 64%

Resolution 21%

Brightness 15%"

"What this means to the HDTV viewer is that the vertical resolution of any HDTV pictures that have a vertical motion component is better in 720P than in 1080i. Based on the above findings, progressively-scanned images equivalent to the observed dynamic vertical resolution of 1080i may be achieved using only 648 lines. If we want to play a numbers game, 720P has better dynamic vertical resolution than 1080i by 72 lines."
"We have seen that interlaced scanning was born as a compromise to conserve analog bandwidth; a compromise that results in picture impairments and artifacts. A DTV broadcast is limited not by analog bandwidth but by digital bandwidth: the critical limitation is on the number of digital bits per second that may be transmitted. In order to broadcast DTV pictures, their bit rate must be aggressively reduced by digital compression to fit within the broadcast channel or pipeline that is available. The digital bits representing HDTV pictures must be compressed by a ratio that averages around 70 to 1 in order to fit into the 19 megabit-per-second DTV transmission channel. This creates a "funnel effect": for each 70 bits that enter the funnel's large end, only a single bit passes through the small end of the funnel into the transmission channel. Digital compression technology is improving rapidly, but it has been consistently observed that 720P HDTV pictures may be compressed much more aggressively than 1080i pictures before they become visually unacceptable. In fact, compression of 1080i pictures routinely generates visible artifacts, particularly when the pictures contain fast motion or fades to or from black. These artifacts cause the picture to degenerate into a blocky, fuzzy, mosaic, that may be observed frequently in 1080i broadcasts. The stress level to the HDTV broadcast system caused by bit rate reduction is much lower for 720P, and blockiness artifacts are seldom observed in 720P broadcast pictures. It may be expected that 720P will always lead 1080i in compressibility and freedom from compression artifacts, because progressive scanning is by its nature superior in the area of motion estimation. This gives it a "coding gain" relative to interlaced scanning, and the result will always be delivery of the same picture quality at a lower bit rate.

Finally, let's take a closer look at the display. The resolution of any type of display is dependent on its dot pitch, which effectively defines the physical size of the dots, or screen pixels: the higher the resolution, the smaller each dot must be. We see this when considering computer monitors or printers: a 600 dot-per-inch printer makes a sharper image than a 300 dot-per-inch printer, and a 0.28 dot-pitch monitor makes a higher resolution image than a 0.50 dot-pitch monitor, and of course the higher resolution printer and monitor cost more than their lower-resolution counterparts.

In order to fully resolve a 1080i picture, a display screen must have about 6 million dots, and for 720P, the figure is about 2.75 million dots. The larger the number of dots required, the smaller each dot must be, and the smaller the dot, the less light it generates. The full resolution of 720P may be displayed using dots three times larger than 1080i for a given screen size, and this gives the HDTV viewer a brighter picture with a higher contrast ratio. As an added bonus, the lower resolution display is less expensive to make."
"720P, when compared with 1080i, provides better dynamic resolution, better motion rendition, the absence of interlace artifacts, and the absence of compression artifacts. It makes brighter pictures with a higher contrast ratio than 1080i".


http://www.bluesky-web.com/numbers-mean-little.htm

720p wins..."GAME OVER"!
post #1285 of 1457
I thought this was 1080p vs 720p thread? Not that I disagree with you.
post #1286 of 1457
Quote:
Originally Posted by Sole_Survivor View Post

Despite all the facts with links, and tests results I presented in this thred, like a religion, people stuck up for 1080 interlaced. Here is a link (another one) that proves 720p is better. I claim victory not only with the official test by the EBU in my signature, but read this.

"The advocates of 1080i HDTV support their cause with a flurry of numbers: 1080 lines, 1920 pixels per line, 2 million pixels per frame. The numbers, however, don't tell the whole story. If we multiply 1920 pixels per line times 1080 lines, we find that each 1080i frame is composed of about two million pixels. 1080i advocates are quick to point out that a 720P frame, at 1280 pixels by 720 lines, is composed of about one million pixels. They usually fail to mention that during the time that 1080i has constructed a single frame of two million pixels, about 1/30 second, 720P has constructed two complete frames, which is also about two million pixels. Thus, in a given one-second interval, both 1080i and 720P scan out about 60 million pixels. The truth is that, by design, the data rates of the two scanning formats are approximately equal, and 1080i has no genuine advantage in the pixel rate department. In fact, if the horizontal pixel count of 1080i is reduced to 1440, as is done in some encoders to reduce the volume of artifacts generated when compressing 1080i, the 1080i pixel count per second is less than that of 720P.

The actual numbers are 55,296,000 for 720p and 62,208,000 for 1080i. So about 60 million? Or how about 1080i has 12.5% more than 720p. Can we see the differencer, who knows, but just pointing out you scan spin numbers how you want. And the part about reduction to 1440, sure it can be done. Not as much now as in the past. But I can compress 720p as much as I want or muck with the signal too.

Quote:
Originally Posted by Sole_Survivor View Post

Another parameter 1080i advocates use to advance their cause is resolution. Resolution is the ability to preserve the separate components of fine detail in a picture, so that they may be discerned by the viewer. But picture quality is not dependent on resolution alone. Numerous studies of perceived picture quality reveal that it is dependent on brightness, color reproduction, contrast, and resolution. Color reproduction is identical in all HDTV scanning formats, and may thus be disregarded as a factor. A typical study assigns the following weights to brightness, contrast, and resolution:

Contrast 64%

Resolution 21%

Brightness 15%"

Sure resolution is not tops on the list for PQ. But that doesn't take away from the fact that 1080i is still better.

Quote:
Originally Posted by Sole_Survivor View Post

"What this means to the HDTV viewer is that the vertical resolution of any HDTV pictures that have a vertical motion component is better in 720P than in 1080i. Based on the above findings, progressively-scanned images equivalent to the observed dynamic vertical resolution of 1080i may be achieved using only 648 lines. If we want to play a numbers game, 720P has better dynamic vertical resolution than 1080i by 72 lines."

I think you meant to quote more than what is here. There is no data to back this up.

Quote:
Originally Posted by Sole_Survivor View Post

"We have seen that interlaced scanning was born as a compromise to conserve analog bandwidth; a compromise that results in picture impairments and artifacts. A DTV broadcast is limited not by analog bandwidth but by digital bandwidth: the critical limitation is on the number of digital bits per second that may be transmitted. In order to broadcast DTV pictures, their bit rate must be aggressively reduced by digital compression to fit within the broadcast channel or pipeline that is available. The digital bits representing HDTV pictures must be compressed by a ratio that averages around 70 to 1 in order to fit into the 19 megabit-per-second DTV transmission channel. This creates a "funnel effect": for each 70 bits that enter the funnel's large end, only a single bit passes through the small end of the funnel into the transmission channel. Digital compression technology is improving rapidly, but it has been consistently observed that 720P HDTV pictures may be compressed much more aggressively than 1080i pictures before they become visually unacceptable. In fact, compression of 1080i pictures routinely generates visible artifacts, particularly when the pictures contain fast motion or fades to or from black. These artifacts cause the picture to degenerate into a blocky, fuzzy, mosaic, that may be observed frequently in 1080i broadcasts. The stress level to the HDTV broadcast system caused by bit rate reduction is much lower for 720P, and blockiness artifacts are seldom observed in 720P broadcast pictures. It may be expected that 720P will always lead 1080i in compressibility and freedom from compression artifacts, because progressive scanning is by its nature superior in the area of motion estimation. This gives it a "coding gain" relative to interlaced scanning, and the result will always be delivery of the same picture quality at a lower bit rate.

I won't deny that 720p compresses better as bandwidth is reduced. But give me the full 19Mbps for OTA transmission and I'll take 1080i. So source-wise 1080i should be better, but I realize that stations continue to add subchannels and compress things to reality is 720p may be better only because the further screw with the signal. So provider issue not source resolution issue.

Quote:
Originally Posted by Sole_Survivor View Post

Finally, let's take a closer look at the display. The resolution of any type of display is dependent on its dot pitch, which effectively defines the physical size of the dots, or screen pixels: the higher the resolution, the smaller each dot must be. We see this when considering computer monitors or printers: a 600 dot-per-inch printer makes a sharper image than a 300 dot-per-inch printer, and a 0.28 dot-pitch monitor makes a higher resolution image than a 0.50 dot-pitch monitor, and of course the higher resolution printer and monitor cost more than their lower-resolution counterparts.

In order to fully resolve a 1080i picture, a display screen must have about 6 million dots, and for 720P, the figure is about 2.75 million dots. The larger the number of dots required, the smaller each dot must be, and the smaller the dot, the less light it generates. The full resolution of 720P may be displayed using dots three times larger than 1080i for a given screen size, and this gives the HDTV viewer a brighter picture with a higher contrast ratio. As an added bonus, the lower resolution display is less expensive to make."
"720P, when compared with 1080i, provides better dynamic resolution, better motion rendition, the absence of interlace artifacts, and the absence of compression artifacts. It makes brighter pictures with a higher contrast ratio than 1080i".



http://www.bluesky-web.com/numbers-mean-little.htm

720p wins..."GAME OVER"!

LOL, larger pixels gives a brighter display, sure. Also means I can see them easier and need to sit farther away so I don't have screen door effect. Talk about spin.

Not trying to be argumentative, just saying there are two sides to the story you posted and numbers can be spun any way you want.

To me the reality is 19mbps OTA 1080i is the superior format. Problem is stations and providers mess with the signal so much and 720p can handle that better. But that doesn't make it better. I still prefer 1080i for all sporting events as it has a much sharper image. Sure, depending on the station there are artifcats sometimes during fast motion. But 720p is ALWAYS soft to me. That is the trade-off for me.
post #1287 of 1457
I'm glad everyone seen that comeback, screen door effect makes 1080i better.

Hail Mary time!

Games over!
post #1288 of 1457
Quote:
Originally Posted by Sole_Survivor View Post

I'm glad everyone seen that comeback, screen door effect makes 1080i better.

Hail Mary time!

Games over!

You do realize your post is the one that said it needed more pixels to fully display all resolution of 1080i. More pixels at higher density yields less screen door effect. Has nothing to do with source resolution.
post #1289 of 1457
Quote:
Originally Posted by Paul Clancy View Post

I thought this was 1080p vs 720p thread? Not that I disagree with you.

You're right, but this thread went off track through the years. I'll agree that 1080p is better with blu ray, but 24 frames can not compare to 60 frames when watching sports. Since all monitors are now progressive, my point is interlaced signals are garbage and you're better with 720p.

People had it in Their head that the tv should deinterace rather than the box, but I disagree. Your body has an immune system, that can fight off some forms of bacteria in water. Years ago they had a fidelity test, where a woman drank water with dirt in it off the floor, if she got sick, or lost the baby, it was thought she was guilty of cheating. This witch doctors test (Numbers 5) we now know had to do with the immune system. Some had a stronger immune system than the other. Either way, the body feels sick when fighting it, making the body work harder. Today we filter water by Britta, and others to keep the body from working less to fight off bacteria etc.
By feeding your body garbage is the same as feeding your progressive monitor interlaced garbage by making your TV work harder. I have plasmas, LCDs, I have performed this test many times. Like the EBU, 720p wins. Your TV is not deinterlacing 1080i to 1080p, it has be proven that 1080i is not 1920, but reduced to 1440 H even 1035p. Not a 1.1 mapping. The 2 broken interlaced fields were designed for an interlaced system. It has been been proven from multiple sources that 1080i has artifacts not seen in 720p. this is why technology evangelist said to keep interlaced signals off your progressive monitor. "stay with 720p if at all possible" see here. http://www.youtube.com/watch?v=Z-JXf...e_gdata_player

It's a slam dunk guys, the EBU ruled on it as well. " FORGET ABOUT IT"!
I have seen no evidence other than from forum members that contradict all the links I have provided.

BTW, I see no screen door on my Plasma. If your tv does not look better in 720p than your cable or sat provider has a ****** box, and fails to properly convert 1080i to 720p. Years ago I posted a link where many boxes and TVs failed the 720 conversion test by chopping off half the signal, and upconverted only 540.
post #1290 of 1457
Quote:
Originally Posted by Sole_Survivor View Post

You're right, but this thread went off track through the years. I'll agree that 1080p is better with blu ray, but 24 frames can not compare to 60 frames when watching sports. Since all monitors are now progressive, my point is interlaced signals are garbage and you're better with 720p.

Why not 1080p60 instead of 720p60?
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