High vs standard definition , idealised comparisson

[Mr.D]

http://www.avforums.com/forums/attac...1&d=1145785545

first one is 8bit 1920x1080 derrived from a 2048x1556 10bit log film scan (analagous to a datacine)

2nd one is the same image downsampled to 720x576 (sinc) and resampled back up to 1920x1080 (lanczos) then cropped the same way as the first image.

same size but hd vs sd resolution so you can see the difference. See how close you need to be to your screen to spot the difference.

These are idealised images and probably went through an image pipeline that is better than any you'll see in a real world system hd or sd version. So you are seeing the best of both worlds. Colourspace is full range 8bit rgb in both cases , no component colour sampling.

[pinkprobegt]

This is the best one I've seen pulled from the Blu-Ray & HD-DVD forum.

It's actual footage!

http://premium1.uploadit.org/TimothyB/HDSD/town_3.gif

[Mr.D]

yep shot off a screen so you've got the display , camera and all the associated processes in between.

[jpb123]

Originally Posted by Mr.D

http://www.avforums.com/forums/attac...1&d=1145785545

first one is 8bit 1920x1080 derrived from a 2048x1556 10bit log film scan (analagous to a datacine)

2nd one is the same image downsampled to 720x576 (sinc) and resampled back up to 1920x1080 (lanczos) then cropped the same way as the first image.

same size but hd vs sd resolution so you can see the difference. See how close you need to be to your screen to spot the difference.

These are idealised images and probably went through an image pipeline that is better than any you'll see in a real world system hd or sd version. So you are seeing the best of both worlds. Colourspace is full range 8bit rgb in both cases , no component colour sampling.

On a 1280x1024 resolution this picture is less than 10 inches. Even with this small a picture the difference is huge. Just look at the teeth and hairs esp the single ones that is across the eye. I see the difference 10 feet away. I'm a firm HD believer but here the difference is so big even I got to wonder if it's a fair comparasion. Have no idea how correct the comparasion is in regard to "real" movies.

[Rimmer]

Originally Posted by Mr.D

These are idealised images and probably went through an image pipeline that is better than any you'll see in a real world system hd or sd version. So you are seeing the best of both worlds. Colourspace is full range 8bit rgb in both cases , no component colour sampling.

Won't the jpeg compression have reduced the colourspace to 4:2:0 component though?

[Mr.D]

Possibly I'm not an expert on jpegs. Regardless it will be the same for both images, this is a resolution comparrison soteh colourspace is somewhat immaterial.

[Mr.D]

Originally Posted by jpb123

I'm a firm HD believer but here the difference is so big even I got to wonder if it's a fair comparasion. Have no idea how correct the comparasion is in regard to "real" movies.

If anything I'd say the SD version is somewhat better than what you'll see off most sd pipelines. For a start it hasn't been vertically filtered and the downsampling is probably using algorthims that probably wouldn't work in real time and the image precision is at least 16bit from end to end.

Both examples are probably a good bit better than either standard or high definition flavours you'll get in the home...as such I'd say its a good comparisson to give an idea what sort of differences you should see.

[welwynnick]

I don't understand; those pictures are only about 450 lines. Are they supposed to represent a full screen or just a segment of a screen, and preserved pixel for pixel?

I do think the HD shot is rather better BTW, but I do think DVD can also look marvelous when upscaled well.

Nick

[Mr.D]

Originally Posted by welwynnick

just a segment of a screen, and preserved pixel for pixel?

Nick

yes

[Pecker]

Maybe I'm going blind, and so are all my collegues. We've just looked at those two pics on several different monitors and, whilst the HD shot is clearly sharper, the difference isn't the gulf you lot are talking about.

Strangely enough, some other unusual sources appear to agree.

The Digital Bits has been championing the coming of HD for months (years?), and yet their opinion on seeing the finished product appears to be very similar to mine:

http://www.thedigitalbits.com/mytwocentsa119.html#noir

I was particularly interested to hear that:

"All of this goes to my point, which is this: HD-DVD looks and sounds fantastic... just as we all expected it would. I have little doubt that Blu-ray Disc will look and sound just as good too - not better than HD-DVD mind you, but every bit as good. But how good does the video and audio quality REALLY have to get for most people to enjoy a film in their living rooms? Standard DVD looks and sounds great just as it is - it was a MASSIVE improvement over VHS and laserdisc. And the better your equipment is (and keep in mind that most people still haven't upgraded to widescreen HDTVs, upconverting DVD players and true multi-channel surround sound), the average experience of DVD is going to keep improving. There's tremendous value to be found in existing DVD, just as it is, and that will continue to be the case for years to come. So how many people are REALLY going to care enough to upgrade to a new high-definition videodisc format? How about TWO high-definition videodisc formats? Not that many, I'll bet.

Maybe, eventually, if and when there's only ONE format so people can feel comfortable spending their money on it... they'll start to upgrade to either HD-DVD or Blu-ray Disc in moderate numbers. But for now, HD-DVD and Blu-ray Disc will likely remain the domain of only the most enthusiastic early adopters. And the longer the format war drags on, the greater the chance that even those consumers who MIGHT be interested will just pass on both of them, in favor of HD offerings from their cable or satellite provider, downloading... or just plain old standard DVD (like most audio consumers passed on much higher quality DVD-Audio and SACD, in favor of far lower quality iTunes or MP3 downloads, satellite radio and current CDs). DVD became the success it is not just because it had better quality going for it over VHS and laserdisc, but because it had significantly better value and convenience going for it too. HD-DVD and Blu-ray Disc offer the same basic value and convenience as regular DVD, so the only real improvement is the video and audio quality. And better quality isn't always enough to separate people from their cash.

I'm certainly not trying to be a pessimist, just realistic. As cool as they are, I'm afraid I don't see HD-DVD or Blu-ray Disc becoming even half as successful as current DVD... and that's BEST case, if one of them quickly stands out as the clear and obvious choice to consumers (something I fear that isn't going to happen anytime soon). Time will tell."

And over at IMDB they're Saying:

http://www.imdb.com/news/sb/2006-04-20

Notably:

"On smaller sets, the writers agree, the difference between HD DVD and a conventional DVD is virtually undetectable. "Bottom line is that HD DVD is great, but will you notice?" asks Ben Drawbaugh on HDBeat.com. Writing in the Los Angeles Times David Colker remarked that on larger screens he could detect a subtle difference. He added: "I tested my perceptions by switching between the two formats. I asked a colleague to close his eyes while I chose a version, then had him open them and guess: DVD or HD DVD? He got it right only about 75% of the time. So, yes, it's better. But don't expect the dramatic leap in quality that came with the transition from VHS to DVDs in the 1990s."

All-in-all these stories merely underline the point - HD is better than PAL/NTSC, but not nearly as big a jump as there was between VHS & DVD.

Steve W

[tryingtimes]

Well I guess that's why it's useful to see pictures like these - you've obviously seen that the differences aren't worth it to you in your particular environment.

I, on the other hand, see chalk and cheese (+ have a 100" screen)

I know who's going to be the more in debt

[CrispyXUK]

Thanks Mr. D, I've been meaning to do one of these comparisons for a while, ableit with a WMVHD source, it really does show the improvement HD makes but also makes you aware of how little difference it will make with a moving image, no doubt this could be the next SACD/DVD-A.

[Mr.D]

Originally Posted by Pecker

Maybe I'm going blind, and so are all my collegues. We've just looked at those two pics on several different monitors and, whilst the HD shot is clearly sharper, the difference isn't the gulf you lot are talking about.

I'm not making any judgements as to what people should think. Put it this way if I sit more thna about 6 feet back from a 24" CRT monitor displaying these images then I can't readily identify which is which.

If I sit 10 feet back from my panny 42PHD8 I can still just pecieve the better hair detail.

I've not had time to see what sort of difference I can actually see on my sony HS20 from 10 feet back but certainly from previous viewings of hd material its the one that will show things up.

If I had a 32" lcd I wouldn't bother going hidef on it.

[Mr.D]

Originally Posted by CrispyXUK

it really does show the improvement HD makes but also makes you aware of how little difference it will make with a moving image,

Not sure I follow you , motion doesn't really come into it.
I certainly don't regard hidef as being a necessity below a certain screen size but then again that almost goes without saying.

The way I've always described it is that hidef makes a 9 foot screen look as sharp as an sd 32" screen at normal viewing distances. The main problem with large screens is the resulting inevitable softness but hidef counteracts that very succesfully.

So I'm all for it but I don't think it will ever be the must have purchase that dvd was. Hidef will gradually replace sd over time as the cost of the sets come down and the consumers percieve they are getting added benefit for their nominal expenditure ...exactly like nicam if anything. Pretty soon it became ubiquitous but never really essential for the majority.

I'm sure hidef will go the same way.

[CrispyXUK]

Originally Posted by Mr.D

Not sure I follow you , motion doesn't really come into it.
I certainly don't regard hidef as being a necessity below a certain screen size but then again that almost goes without saying.

What I mean is that staring at a static frame is easier to see the difference, in motion it will be harder to see the improved detail if you know what I mean