Interesting image quality comparison - 700mb XVid, DVD, 720p & 1080p

[Neil]

The following image gives four image comparisons, showing a 700mb XVid vs DVD (576p) vs 720p vs 1080p - http://plastik.hu/media/irobot-4fele.jpg

Interesting how:-
- The Xvid isn't much worse than the DVD.
- There is little difference between 720p and 1080p.

[MinionZombie]

Interesting.

Although I've never watched a DVD that looks that shitty, nor an Xvid that looks that shitty - both look better when I watch them, especially DVD which is far better than that by a long shot.

Xvid's used for DVD rips mostly though, so it makes sense that they're pretty similar.

[Neil]

Interesting.

Although I've never watched a DVD that looks that shitty, nor an Xvid that looks that shitty - both look better when I watch them, especially DVD which is far better than that by a long shot.

- Don't forget all those images are magnified up to 1920x1080, so issues on the poorer quality images are more obvious.
- Static images always seem to look worse than moving ones.



Xvid's used for DVD rips mostly though, so it makes sense that they're pretty similar.

Yes, but the Xvid is only 20% of the size. That's quite impressive compression! :)

[MinionZombie]

Aye, fair play on both counts - I figured the image was blown up, but couldn't be arsed to mention it. :D

And aye, good point about Xvid too. Spiffing compression.

[axlish]

The following image gives four image comparisons, showing a 700mb XVid vs DVD (576p) vs 720p vs 1080p - http://plastik.hu/media/irobot-4fele.jpg

Interesting how:-
- The Xvid isn't much worse than the DVD.
- There is little difference between 720p and 1080p.

The images need to be in motion to see the real difference. It'd be like looking at a soundwave graph and being amazed at the similarities between 64kbps audio and WAV audio.

[kidgloves]

There's a massive difference between 720p & 1080p or even 1080i. You only notice it when viewing it on bigger screen. It also depends on how close you're sat near the screen. It's not something you can judge on a monitor/tv

[Neil]

There's a massive difference between 720p & 1080p or even 1080i. You only notice it when viewing it on bigger screen. It also depends on how close you're sat near the screen. It's not something you can judge on a monitor/tv

I can fully understand that. But in my case I have a 37" TV and sit 6ft away, so I doubt very much if I could notice the difference between 720 & 1080p... But I'm sure I would notice the difference between DVD and 720p...

[DjfunkmasterG]

When you get above 50" there is a noticable difference between 720P and 1080P, but anything under that is hard to really see a difference.

[Neil]

When you get above 50" there is a noticable difference between 720P and 1080P, but anything under that is hard to really see a difference.

I suspect on smaller TVs, if you're close you might, but as you say I bet it's subtle...

[PJoseph]

What's really crazy about this is that I Robot still looks like crap in all resolutions.

pJ

[DjfunkmasterG]

Gotta agree, I,ROBOT is one of the worst HD transfers out there, however The Perfect Storm takes the cake.

Most people usually grab from Transformers, King Kong or.. Shooter to show off great HD work.

[axlish]

The best HD demo disc I have bought so far is Hellboy 2. I wasn't wild about the flick, but the a/v kept me entertained.

[CoinReturn]

Romero's Dawn of the Dead looks phenomenal on BluRay. Day of the Dead...not so much :(

[SymphonicX]

Guys I think you may be missing a trick here. (not talking about Xvid here really)


The images are all the same aspect ratio and size (H and W), on that webpage. Meaning that there is no possible way that the first image and the last image would come out the same on your screen, the 1080p image should be traversing off your internet explorer window and need to be scrolled to view it, if it was a 1080 image, whilst the 576 image would be sizably smaller.

As it stands one of the ratios of the jpeg equals 1920 - meaning that the HD image is probably true assuming that the 1080 lines are still in tact - which means that the SD image has been stretched out to match the HD one, invalidating the comparison.

HD isn't about "better quality" per se, it's about a higher resolution which leads to better image quality because there are more pixels in the picture (ie: a BIGGER picture)- the images you've got there are simply all of the same pixel ratio therefore not an indication of what you'd experience whilst actually watching these things in their native formats.

The only way to do a true SD HD comparison is to have an SD TV and a HD TV synchronised and playing the same thing. Even in Tescos the Sky HD and SD comparison is actually far better in terms of SD image quality than you'd get in a normal domestic environment because all the footage was ingested as up-res'd SD and laid off to tape as up-res'd SD and true HD. (I know, because I helped make them:))

Did that make sense? I guess in a nutshell I'm saying - the only way you're going to see a true comparison is in a room with those machines playing them natively - as soon as you put it into a computer environment ie: the internet, it loses the point entirely - think of it as though someone is photographing their brand new HD TV to prove to a web forum how great the picture quality is...lol

[Neil]

Guys I think you may be missing a trick here. (not talking about Xvid here really)


The images are all the same aspect ratio and size (H and W), on that webpage. Meaning that there is no possible way that the first image and the last image would come out the same on your screen, the 1080p image should be traversing off your internet explorer window and need to be scrolled to view it, if it was a 1080 image, whilst the 576 image would be sizably smaller.

As it stands one of the ratios of the jpeg equals 1920 - meaning that the HD image is probably true assuming that the 1080 lines are still in tact - which means that the SD image has been stretched out to match the HD one, invalidating the comparison.

HD isn't about "better quality" per se, it's about a higher resolution which leads to better image quality because there are more pixels in the picture (ie: a BIGGER picture)- the images you've got there are simply all of the same pixel ratio therefore not an indication of what you'd experience whilst actually watching these things in their native formats.

The only way to do a true SD HD comparison is to have an SD TV and a HD TV synchronised and playing the same thing. Even in Tescos the Sky HD and SD comparison is actually far better in terms of SD image quality than you'd get in a normal domestic environment because all the footage was ingested as up-res'd SD and laid off to tape as up-res'd SD and true HD. (I know, because I helped make them:))

Did that make sense? I guess in a nutshell I'm saying - the only way you're going to see a true comparison is in a room with those machines playing them natively - as soon as you put it into a computer environment ie: the internet, it loses the point entirely - think of it as though someone is photographing their brand new HD TV to prove to a web forum how great the picture quality is...lol

No, what the image it trying to convey is the different image quality in the four different formats.

The image is trying to show if you showed all four formats on a 1080p TV roughly what you'd get. The DVD for example would pushed into the TV (most likely) at 576p, and the TV would magnify it up to 1080p. Now of course the TV may do some trickery (anti-aliasing?) to make the lower resolution image looked better/smoother on the high resolution that just a dumb magnification, but the basic effect is that those four images give a relatively good indication of the quality of the source being supplied by those four sources...

[SymphonicX]

No, what the image it trying to convey is the different image quality in the four different formats.

The image is trying to show if you showed all four formats on a 1080p TV roughly what you'd get. The DVD for example would pushed into the TV (most likely) at 576p, and the TV would magnify it up to 1080p. Now of course the TV may do some trickery (anti-aliasing?) to make the lower resolution image looked better/smoother on the high resolution that just a dumb magnification, but the basic effect is that those four images give a relatively good indication of the quality of the source being supplied by those four sources...


Ahh well that's entirely different....if you got a 1080p TV then why would you worry how crap your already crap SD signal is, and bother comparing it? (although I see the Xvid comparison as useful somewhat). It's kinda like saying "this printer is great but look how crap it looks when I print this 200x300 image on a billboard"...well...erm.....

But there you go, a true comparison....stand in a room with a CRT SD TV and a 1080p HD TV or better still a JVC DTV multicomponent monitor viewing uncompressed HD output of a Sony HDCAM SR deck....mwahaha

Good fun though, thanks for posting...I love these things....shame we can't take the telly out of the equation though and see the real difference in quality, but hey ho.

[PJoseph]

I can tell you this. When we online full rez at 1080 in a suite with HD monitors, it looks great. However, for home - and for the cost and size - 720 is still fantastic. Eventually, everyone will broadcast in 1080 and the TV's will be cheaper, so it won't really matter.

I do enjoy flipping the channel between the HD broadcast and the SD broadcast on my buddies TV - it's like your watching TV in the future...and then TV from the 80s.

pJ

[axlish]

Romero's Dawn of the Dead looks phenomenal on BluRay. Day of the Dead...not so much :(

Day of the Dead looks fucking amazing, seriously. Pop it in again and re-evaluate. After watching the stunning Day of the Dead transfer on Blu-ray, immediately watch The Many Days of the Dead featurette and pay close attention to the 480i clips of the film and see how weak they look in comparison.

Dawn of the Dead looks good, but nowhere near the improvement that Day is.

[SymphonicX]

I can tell you this. When we online full rez at 1080 in a suite with HD monitors, it looks great. However, for home - and for the cost and size - 720 is still fantastic. Eventually, everyone will broadcast in 1080 and the TV's will be cheaper, so it won't really matter.

I do enjoy flipping the channel between the HD broadcast and the SD broadcast on my buddies TV - it's like your watching TV in the future...and then TV from the 80s.

pJ

the company I work for broadcasts in 1080i, which is amazing, unfortunately 1080p is prohibitive at the moment, but no one really cares...lol

Uncompressed HD on a tape, bitrate = 1gb per SECOND...that's 60 gigs a minute....mad huh? You can fill a 1TB HD with 1hr 40 mins of uncompressed material.

However as soon as it's out of the deck and into an Avid it gets compressed to fuck, depending on the codec used (we use DNX120 and DVCpro), but still runs at about 1gb per MINUTE....

However....when it gets to your set top box, the chances are it's similar to what we do and that's 8mbs per second...

so thinking about that....1gb per second compressed to 8mb per sec, pretty amazing considering if you put them side by side the difference is negligible to the untrained eye...

[EvilNed]

I actually think there's a pretty big difference between the DIVX picture and the DVD picture. And I've always thought the DIVX to be nowhere near as clear as DVD.

[Neil]

I actually think there's a pretty big difference between the DIVX picture and the DVD picture. And I've always thought the DIVX to be nowhere near as clear as DVD.

Depends on the compression ratio of the DivX/XVid... In the example above the file is probably 20% of the original's size...

[axlish]

If minimized down to appropriate pixel size on a pc monitor, xvid/divx can look pretty sharp. Put on any television over 20", and it'll look like pixels holding hands.

[DubiousComforts]

Day of the Dead looks fucking amazing, seriously.
I agree, and it's unbelievable that there are still debates regarding whether or not HD is a significant improvement when the facts aren't debatable. I posted some DAY screencap comparisons (http://forum.homepageofthedead.com/showthread.php?t=8280&highlight=dead&page=3) almost two years ago to demonstrate the significant differences. And I still don't have so much as a Blu-ray drive for my PC, yet it's plainly obvious to me.

[EvilNed]

If minimized down to appropriate pixel size on a pc monitor, xvid/divx can look pretty sharp. Put on any television over 20", and it'll look like pixels holding hands.

Yeah. That's a pretty good point. Never had a problem when watching DivX on the computer. But on a big screen TV it shows.