Star Wars GOUT in HD using super resolution algorithm (* unfinished project *) — Page 20

I was there, hanging around, some minutes to waste, so... here you are my comparison:
http://screenshotcomparison.com/comparison/125694

I leave the task to DrDre, but sometimes I like to post my own comparison, just to spur him to do his best! (^^,)

About AR: I love to have as much picture as possible, and I hope DrDre will change his mind, and use all the sides information, becase they are mean to BE there! On the height: 548px is the perfect size, as it's exactly 2x the GOUT, and gives better results and less artifacts on the vertical direction.

Still don't get the connection between 704 and 640, when both 704 and 720 are valid DVD resolutions... may you explain your decision?

DrDre, I'll be glad if you would like to take some time to write an article about the SuperResolution method on fanres! You have certain more knowledge about it than me, and it will be a great thing to have an essay, written by someone who actually uses it, and not from a software house... thanks in advance!

That's great, thanks a lot; community will be happy to read it - me too, of course!

thorr said:

[...] check it vs. the Blu-ray which most likely is correct.

DrDre said:

It was CatBus who provided this information thankfully. So all credit should go to him. I didn't know about this, but was struggling with getting the correct AR.

This will get you the AR that the people who made the GOUT (or more accurately, the Definitive Collection Laserdisc) intended for that video release to have.  What relation that has to the actual film's AR is a matter of debate.

If you're aiming for "just the GOUT without extra fix-ups" then what you've done is right.  If you're actually aiming for correct, I think you should refer to another reference, although I'd try to use footage from -1, rather than the Blu-rays for that AR reference.

If 704 is related to 640, then 640/2.35=272... if you have a picture 274 pixel height, then 274x2.35=643.9

So 704/640=1.1 then 643.9x1.1=708.29 - that is (a bit) nearer to 712 than 704... (^^,) - so, at least you should crop at 708 than 704.

Also, dicrepancy is tiny, so I'd prefer to have a really small error in aspect ratio, retaining more picture, than having a "right" aspect ration, losing some details that could be precious - as much as a little bit than 1% could be considered precious, of course!

DrDre said:

The standard for NTSC is that the 8 outermost pixels should be blank and are meant for cropping and not be displayed. The centre 704 pixels contains the video and determine the AR. These are displayed as 640x480 square pixels for a 4:3 AR. So if you remove the black bars and rescale the GOUT to it's correct AR, you get a 640x274 video with an AR of 2.34:1. If you then upscale by a factor of 2, you have a video of 1280x548. Now as you have noticed the blank areas of the GOUT are not entirely blank. They contain video. However if you were to upscale the 714x274 video to 1280x548 (the left 4 pixels and the right 2 pixels are blank for Star Wars) you would get the wrong AR, since the true AR is determined by the centre 704 pixels, not 714 pixels. So I did what was necessary to keep the correct AR and that is the crop the video to 704x274 and upscale to 1280x548.

This all assumes a DVD properly mastered to the true "Blue Book" (DVD Forum) specification.

Cropping a D-1 master from 720x486 to 720x480 and dumping to DVD (as is the case with the GOUT) does not result in an up-to-spec DVD.

D-1 PAR is retained, for instance, and is not 640/704≈0.9091 as is assumed here.

The active picture area for D-1 is 710.85 with a PAR of 4320:4739≈0.9116. The closest digital approximation of this is obtained via rounding up to 711 and slightly modifying the PAR to 72:79≈0.9114.

Notice how 711*72/79=648 and 648/486=4/3. Yes, that's = here, not ≈.

NTSC GOUT has 712 active pixels horizontally (most D-1 machines do 712 rather than 711 to make 4:2:2 work). Where do you see 714?

Check out: http://xpt.sourceforge.net/techdocs/media/video/dvd/dvd04-DVDAuthoringSpecwise/ar01s02.html

AntcuFaalb said:

Cropping a D-1 master from 720x486 to 720x480 and dumping to DVD (as is the case with the GOUT) does not result in an up-to-spec DVD.

I think it's fairer to say you just end up with a distorted AR than an out-of-spec DVD, but I know what you mean.  The distortion is baked in.

I think that puts a point on the question of what exactly this project is doing--a warts-and-all GOUT fixup (in which case distorted AR might be preserved), or something more akin to the actual theatrical prints (in which case they may want to skip right past the D1 master--which might have its own issues--and go to a theatrical print as the reference)

CatBus said:

AntcuFaalb said:

Cropping a D-1 master from 720x486 to 720x480 and dumping to DVD (as is the case with the GOUT) does not result in an up-to-spec DVD.

I think it's fairer to say you just end up with a distorted AR than an out-of-spec DVD, but I know what you mean.  The distortion is baked in.

Agreed.

CatBus said:

I think that puts a point on the question of what exactly this project is doing--a warts-and-all GOUT fixup (in which case distorted AR might be preserved), or something more akin to the actual theatrical prints (in which case they may want to skip right past the D1 master--which might have its own issues--and go to a theatrical print as the reference)

Are we sure the AR is truly distorted? I think we should make a distinction in this circumstance between distortion and cropping.

The GOUT is only missing 2 scanlines to make it a proper 2.35:1 release (648x274 at 1:1 PAR rather than 648x276 at 1:1 PAR).

A distortion in this context would imply that a circle drawn on the film (after applying an anamorphic lens) would not be a circle in the GOUT after PAR correction and I'm just not sure that that's the case.

The easiest solution to this would be to grab a frame from the film, apply anamorphic stretch, downscale to get it close to GOUT, get the cropping close, and then apply an image registration algorithm to spatially align the two images.

I'll grab a frame from our 35mm IB scan tonight. Do you have any particular frame in mind? I have reels 2-6 currently.

AntcuFaalb said:

NTSC GOUT has 712 active pixels horizontally (most D-1 machines do 712 rather than 711 to make 4:2:2 work). Where do you see 714?

Check out: http://xpt.sourceforge.net/techdocs/media/video/dvd/dvd04-DVDAuthoringSpecwise/ar01s02.html

Great article - that I read years ago, but completely forgot to bookmark...

Now, you are *forced* (in a Star Wars way, of course) to write an article about aspect ratio on fanres! (^^,)

AntcuFaalb said:

I'll grab a frame from our 35mm IB scan tonight. Do you have any particular frame in mind? I have reels 2-6 currently.

Probably any large object with high contrast at the edges, sharply defined.  That way when you're counting pixels, there's less error.

I'd say a Vader closeup in the Tantive IV corridor should be good.  Well-lit, sharp, black and white.

This is the way to get an absolutely correct AR, and thanks for the resources.