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DrDre

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Join date
16-Mar-2015
Last activity
6-Sep-2024
Posts
3,989

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Post
#934499
Topic
Estimating the original colors of the original Star Wars trilogy
Time

Laserschwert said:

Yeah, all the dinner scene “corrections” look totally wrong, with blacks turning into strong blues. It’s especially obvious with the Senator next to it, which doesn’t show this blue sheen at all.

The problem is that in order to make a comparison with the Senator print photos I had to increase the brightness substantially, so a very slight black imbalance [0 0 1] in RGB now becomes [0 0 7], which leads to the blue sheen. I actually know where the imbalance comes from. I updated the algorithm, and forgot to include the black balance. However, it’s easily fixed. I will debug the algorithm, and update the frames.

Post
#934452
Topic
Estimating the original colors of the original Star Wars trilogy
Time

clutchins said:

There’s just that sharp blue sheen in the automated correction and I don’t know where it would come from or why.

There’s a dark purple edge around the raw frames, that is interpreted as color by the algorithm, and therefore also “corrected” to a brighter more obvious blue streak. I didn’t bother to crop the frames before I processed them.

Post
#934441
Topic
Estimating the original colors of the original Star Wars trilogy
Time

It’s interesting to go back to the comparisons for this shot we did a while ago in the bluray regrade thread. Both NeverarGreat and myself presented our regrades based on the available references at the time.

Bluray regrade by NeverarGreat:

Bluray regrade by DrDre:

Automated color correction of LPP:

Senator print photo:

The most important question for this thread is, whether the automated correction provides colors that are accurate enough to be used as a reference? Considering that the automated regrade closely resembles the senator print photos, the Technicolor print scans, and in terms of color appears no less accurate than NeverarGreat’s manual correction, and my own correction of the bluray, I would say it is.

Post
#934421
Topic
Estimating the original colors of the original Star Wars trilogy
Time

While I agree the Luke frame has some problems, that need to be addressed specifically, rather than applying a global correction for the reel as was done in this case, I think, aside from being a bit murky, the colors of the other two frames are very accurate.

Raw scan:

Automated color correction + brightness adjustment:

Senator print photos:

Post
#934381
Topic
Harmy's RETURN OF THE JEDI - Grindhouse 35mm LPP (Released)
Time

I was watching the ROTJ Grindhouse, and was surprised how green some of the exterior shots of the Death Star are, especially in the early shots, and during the space battle at the end. Is this delibirate?

I ran one of the frames through my algorithm, and it came out looking a bit different.

Grindhouse:

Grindhouse + automated correction:

I’m also pretty sure the small planet/moon in the background should be red, at least that’s how it appears in the home video releases, and that’s also what the algo predicts.

Post
#934379
Topic
kk650's Star Wars Saga: Regraded and Semi-Specialized (Released)
Time

towne32 said:

Your algorithm won’t work on scenes that are intentionally filtered a certain color, right? Just wondering for the debate of how blue Hoth night shots should be.

The idea is that you calibrate the algorithm on shots that were filmed during the day, and then correct the night shots with this correction model, which should give you the correct colors for those shots.

Post
#934361
Topic
kk650's Star Wars Saga: Regraded and Semi-Specialized (Released)
Time

kk650 said:

@towne32: What i’m really interested in seeing is how The Empire Strikes Back print looks after the red fade is properly removed, see what the overall colour scheme and fleshtones look like.

I think I can answer that question. I’ve developed an algorithm, that can accurately reconstruct the original colors of a faded print from the print itself, without manual guidance. Here’s what the colors look like for one of the frames piota posted a while ago of his red faded TESB print:

Post
#934005
Topic
Estimating the original colors of the original Star Wars trilogy
Time

towne32 said:

What happens to the uncorrected 35mm Rancor shots with your process? I know Harmy had a tough time dealing with the very different brownish home video versions and blueish film versions.

I would need to have access to a large portion of the first reel to make an accurate estimate of the colors. The correction is in principle always done in relation to other shots to preserve the original theatrical color timing.

Post
#934000
Topic
Estimating the original colors of the original Star Wars trilogy
Time

I’m working on the second reel of the SSE Grindhouse, which is in much better condition than the first reel. Here’s one of the Obi-Wan meets Luke shots before and after the automated color correction.

Before:

After:

Like on the Senator print photos, the automated correction says there should be a blue sky in this shot.

Senator:

To be continued…

Post
#932332
Topic
Estimating the original colors of the original Star Wars trilogy
Time

ScruffyNerfHerder said:

Hey DrDre,
This looks amazing! I make it a point not to swear, but holy shit your work impresses me. 😛 I did have two questions. You use Matlab to create your algorithms, correct? As there is a Mac version of Matlab, is it also possible to create a Mac version of your completed applications? I don’t want to add to your hassles if the process is complicated, but if it’s a matter of hitting a button and spitting out a Mac app, I for one would appreciate it. I do have Bootcamp, and quite a few old photos and videos that I’d love to put through your process either way.

Keep up the amazing work! 😃

Thanks! Sadly, to compile a Mac version of the tool requires that you have a Mac version of MATLAB, and a Mac. Unfortunately, I have neither. An alternative would be to obtain a Mac version of MATLAB, and run the tool from there.

Post
#931816
Topic
Estimating the original colors of the original Star Wars trilogy
Time

hairy_hen said:

It does, and it’s one reason why I’m not altogether thrilled with the idea of eliminating the color tints of DeEd 2.5 and making everything look neutral.

Mike V made this point back when he first introduced us to the idea a few years ago: in order to get back the original colors of the movie, you have to view it through a 70’s-era light source. If you don’t, you’re not seeing it the way the filmmakers or the general public would have seen it at the time. They made their color timing choices by viewing the film through projection equipment of that era, with its warmer and more yellow-tinted output. A neutral light source just doesn’t look right for this movie, because that whole effect is completely removed. The amount of yellow in the image will be significantly reduced compared to how the output would have appeared when the color timing was being done, so in order to see what they would have seen, it has to be put back in.

Obviously very few people are going to be able to project a film print with vintage light source, so incorporating it into the color timing of a release is the only way to actually ensure that it comes across the way it should to the end viewer. Now obviously this doesn’t directly affect what is being done with the algorithm this thread is about, because a neutral color scheme is exactly what it will most easily create. But it is something that needs to be kept in mind for any release that claims to desire color accuracy to the movie’s original appearance.

The movie’s original appearance is exactly what’s on the original print. How it came to be changes nothing. Now, obviously to see the film the way most people saw it back then, you need to project it with a bulb from the era, or a contemporary bulb with similar characteristics, no arguments there. However, this thread is about restoring print colors pure, and simple. Preparing a home video release that is faithful to a 1977 theatrical experience is a separate issue. You say you’re not thrilled about eliminating the color tints of DeEd 2.5. This seems strange to me, as DeEd 2.5 is based on a Technicolor print scan, that was not corrected to the print it’s based on, let alone a print projected with a 70s bulb. Add to this the fact, that the DeEd colors themselves are not an exact match to the colors of the uncorrected scan. The simple reality is, that the DeEd 2.5 color tints are completely unrelated to the bulb characteristics of the era, or any other era for that matter. They are an approximation of the Tech’s characteristics, that include well known problems like a green shift, that poita has argued were an artifact, not present on the other prints that most people saw at the time. Many may prefer the Technicolor print colors, and that’s fine. I’m simply presenting an alternative. In this endeavour, the process I’m using, is the only logical one (to me at least). First recreate the print colors, which is actually the hard part (in the absence of unfaded prints, other than green shifted Technicolor prints), and then add a bulb effect as post-processing. If the print colors are the cake, the bulb effect is the frosting. Seems odd to worry about putting on the frosting, before you have baked a cake.

Post
#931698
Topic
Estimating the original colors of the original Star Wars trilogy
Time

towne32 said:

How would you ever know if it was restored to match the print’s color, then? Even when people are able to match the scan to the print by looking at the projected print while they’re doing it, they are of course matching it to a specific bulb (hopefully the correct one). I mean, the print doesn’t even technically have color without a light source to see it. 😉 I think some bias is required because almost 0% of people are going to be watching it with the ‘correct’ type of bulb, even among the lower percentage of people who will be projecting it in some way. But the print itself doesn’t posses some ‘bulbless’ color state that is both objective and correct, does it?

Of course it does 😃. The “bulbless” color is when you shine white light through it. You should never bias a print during restoration. The bias is introduced when you shine a biased light through it, like a 70s bulb, which has a slight yellow bias. The colors are simply related to the respective amount of dyes, which in turn absorb, red, green light, producing the unbiased colors, if you use an unbiased light source. Now, if you’re interested in making a home video release that mimics a print projected with a 70s light bulb, you could incorporate this in your color grading, but if you’re color grading a print for projection, you definitely want the unbiased colors.

Post
#931660
Topic
Estimating the original colors of the original Star Wars trilogy
Time

CatBus said:

Feallan said:

CatBus said:

Keep in mind, bulb matching is a thing. This is a great way to get the color on the print, but the color on the screen is the color on the print combined with whatever color bias the projector bulb has. So for a seventies bulb, we’re probably talking a little yellower. Not to diminish the importance of this in any way–this will be extraordinarily helpful, but maybe not the final word.

From what I understand, this could relatively easily be incorporated into DrDre’s algorithm. You would need to describe the light used to scan a particular print and the light emitted by a bulb what was in common use when said print had its run in theaters. Of course the accuracy of the final result would depend on how accurate data you fed to the algorithm.

It’s not that it can’t be done, but then you lose the “objectivity” which is part of the draw of DrDre’s method. Choosing the bulb LUT is both subjective (which bulb to choose?) and prone to error. I like what he’s doing, but I see this as more of an initial color correction than a final one, which is really where my comment was headed. You need the objective color correction as a base correction – in fact it’s critical for it to be as objective as possible, and this seems to be doing that – but that doesn’t eliminate the need for subjective corrections afterward.

Well, that depends. In this case it’s about restoring color to a print, and to bring it as close to the original print colors as possible. If that is your goal, this would be the final grading (with some minor asjustments), ready for projection with whatever bulb you fancy. If you want to reproduce some kind of bulb effect on your pc or television screen you still have some work to do, but I would consider that beyond the scope of a restoration.

Post
#931246
Topic
Estimating the original colors of the original Star Wars trilogy
Time

AllAboutThatSpace said:

The results are incredible! Thanks so much!
Definitely putting some scenes into my personal ideal Star Wars 😃
The dark scenes go very dark, is that a feature of the early part of the process or is my screen off whack?

No, the print/scan is the main issue. This is why Team -1 used replacement shots for those. Hopefully the new scan by poita will be able to get some more detail from those scenes. I did not adjust the brightness of the original scan, so a gamma correction would probably improve the final result, but I’m hoping that won’t be necessary with the new scan.