Color matching and prediction: color correction tool v1.3 released! — Page 2

Thanks, I'll get some screenshots later tonight when I'm home. Have either of you attempted to match the blu-ray to other sources?

Here is Blu Ray vs Blu Ray to Gkar

http://screenshotcomparison.com/comparison/138610

http://screenshotcomparison.com/comparison/138611

Here is Gkar vs Blu Ray to Gkar

http://screenshotcomparison.com/comparison/138612

http://screenshotcomparison.com/comparison/138613

Great match once more! 

Holy Shit you guys (DrDre and archimedes), these look great!

-G

Thanks G!

archimedes said:

towne32, if you can provide me some screenshots, then I can do it for you using the PDF method. 

 https://mega.nz/#!2doUEAaA!xfTk12XVv3WqGtRHTFFxowha4Mhqe4_xfBRyUd7Ygl0

Thanks. I'm mostly just curious for what can be done with Harmy's, which seems to be lacking color depth probably due to the scan and subsequent color conversions (and matching up the multiple sources going into it). Included the blu-ray frame for good measure. That GOUT shot sure is a disaster.

g-force said:

Holy Shit you guys (DrDre and archimedes), these look great!

-G

 I agree!

Thanks DrDre, g-force and thorr. 

Here are Harmy and  Blu Ray matched to GOUT colors: 

http://screenshotcomparison.com/comparison/138661

http://screenshotcomparison.com/comparison/138662

As you can see, the PDF algorithm doesn't really work well with bad target images. The colors are matched, but there are problems with the sky and the resulting images are way to grainy.

To reduce the grain artefacts, I implemented the grain removal algorithm described in the paper that also came up with the PDF-algorithm. 

The idea is to match the gradient of the result picture with the gradient of the input picture without losing the colors of the target image. This should reduce the noise introduced by a bad target picture.

Here are the matched GOUT colors compared to the degrain algorithm:

http://screenshotcomparison.com/comparison/138663

http://screenshotcomparison.com/comparison/138664

Here are the final pictures compared to the GOUT:

http://screenshotcomparison.com/comparison/138665

http://screenshotcomparison.com/comparison/138666

The match is indeed pretty good, but grain, crushed blacks, and whites, are an issue for these types of algoritms. I think it could in principle be solved, by adjusting some of steep gradients in the color prediction.

The color prediction I did for Leia frame based on a 35 mm frame, is surprisingly close to a similar frame of Star Wars Legacy Edtion, that Mike Verta posted on his website.

http://screenshotcomparison.com/comparison/138669

I must admit, I really like these more saturated colors. They look really film like.

I hope I will be able to make a small tool for color matching one or multiple frames next week, that everybody can use. Should be relatively straightforward.

Interesting results and impressive given the poor quality of the sources. The general color palette does match well, despite the issues. 

Speaking of Mike, his cleanup on that speeder shot is quite nice: https://vimeo.com/120218626

edit: misunderstood what one of the images was. doh.

DrDre said:

I hope I will be able to make a small tool for color matching one or multiple frames next week, that everybody can use. Should be relatively straightforward.

 You should learn to make (and sell, to those who aren't your OT friends) after effects plugins. :)

The color adjustment is slightly green shifted, like the frame it is based upon. I will do a test next week, where I will adjust SRV13, using Mike Verta's frame as a reference.

DrDre said:

The color prediction I did for Leia frame based on a 35 mm frame, is surprisingly close to a similar frame of Star Wars Legacy Edtion, that Mike Verta posted on his website.

http://screenshotcomparison.com/comparison/138669

I must admit, I really like these more saturated colors. They look really film like.

Wow, I really want Legacy to be released.  That image is absolutely stunning.  Leia's gown is a bit yellow compared to the storm troopers and the skin tones and the rest of the colors are outstanding.

Here's a video sample of The Dark Knight Blu Ray matched to Screener colors. 

https://vimeo.com/136439043

I've used mostly just one rotation, as it went faster this way. There are however, small shots at the beginning that use all rotation matrices, which results in a better matching. 

Here are the three images compared: 

https://vimeo.com/136439044

I'm going to play with the rotaion matrices a little bit. Maybe I will calculate even less than 20, because the matching is really slow, if all 20 rotations are used. There is also sometimes heavy noise, if more than one rotation is used. 

Maybe this would be a way to fix The Lord of the Rings: Fellowship of the rings with the green tint.

That looks really good! How much time did it take to make that clip?

The clip took me about 8 hours to make. However, the first 6 hours were spent on the full rotations. And I started to use multithreading towards the end. 

LOTR can also be fixed. But only if you go the full rotations.

http://screenshotcomparison.com/comparison.php?id=138619

http://screenshotcomparison.com/comparison.php?id=138620

Here's what you get for LOTR with my methodology:

http://screenshotcomparison.com/comparison/138893

Seems to be a very good match.

I did some further tests using a screenshot posted by Mike Verta as a basis. That screenshot was somewhat green shifted, so I first corrected that:

http://screenshotcomparison.com/comparison/138895

I calibrated the color adjustment model on this frame.

Reference versus corrected:

http://screenshotcomparison.com/comparison/138896

Before versus after:

http://screenshotcomparison.com/comparison/138897

Then I used the color correction model to correct three other Tantive IV frames:

http://screenshotcomparison.com/comparison/138898

http://screenshotcomparison.com/comparison/138899

http://screenshotcomparison.com/comparison/138900

If we compare this color correction to Harmy's Despecialized Edition, Harmy's seems pretty green shifted by comparison. Also the red and green highlights in the background and on Vader's belt are much more dull in Harmy's version:

http://screenshotcomparison.com/comparison/138902

The photos of the Technicolor IB print, although not an absolute color reference, seem to suggest the reds are much more highlighted in the Senator print as well:

http://screenshotcomparison.com/comparison/138903

That could indeed have been true. The print coloring probably depended on the type of print stock that was used. The question of course is, whether the green shift was deliberate, or whether age causes the print to become slightly green shifted, and whether the original negative also had this green shift? 

DrDre said:

That could indeed have been true. The print coloring probably depended on the type of print stock that was used. The question of course is, whether the green shift was deliberate, or whether age causes the print to become slightly green shifted, and whether the original negative also had this green shift? 

 That is indeed the question. I am guessing that Mike is doing his work with the answer "no" in mind.

also: Ah! What a terrible time for screenshot comparison to be down. Can't see any of the last few posts worth of work!