Color matching and prediction: color correction tool v1.3 released! — Page 16

brycebayer said:

DrDre said:

thorr said:

I think you nailed it!  How does it look when applying to other scenes?

Also, can you repost the tool.  I went to download it but it is expired.  Thanks!

 It looks oke, but the colors in the bluray are very inconsistent, so each shot definitely needs separate regrading. 

I'm nearly done with v1.3 of the tool. It should be up by tomorrow, and will allow you to export a LUT for use in programs like Nuke and Resolve. 

 Nice!  How are you making the LUTs?  In MathLab?

 Yes, I wrote a script to make the LUTs in MATLAB. I do have to test if they work properly.

Wow. I had almost forgotten how the Pixar movies looked on film. (Though you introduced a weird posterization effect on Buzz's face.)

FrankT said:

I'm getting frustrated - I can't get this tool to operate properly! I've imported the test and reference images, but the "build colour correction model" button doesn't light up. I think I might be doing something wrong. Can you help?

 The tool expects you to correctly crop the test frame, and reference frame. You don't have to, but in that case you have to close the figure window before being able to continue. 

I will make v1.2 available again, because I'm still waiting for some feedback on the LUTs I created.

Link for download: http://we.tl/CKTV8zX6cf (available till the 12th of October) 

FrankT said:

Swazzy said:

Open the test image, then x out of the window that pops up. Open the reference image, and x out of the preview window again. Then building a model will become an option.

 Huh, the instructions didn't mention that. But it works now, so thanks! I'll be back with some of my results.

 I've updated the instructions. 

Starting with this from the Blu-ray :

... to match this from 35mm :

... I obtained this :

So it seems possible to have both the HD from the Blu-ray and the dark creepy mood from the 35mm.

I've developed a new method, called parameter free color correction, for correcting color shifted prints. It in principle has no parameters, and corrects the color with the push of a button. The only variable is a slight contrast adjustment if it is desired, but it works without contrast enhancement. It's also extremely fast. It's done in less than a second. Here are some results for Team Negative1's reel 1 preview:

Just to make this clear. These colors were reconstructed, without any prior knowledge of what the colors should be. 

Tobar said:

Mmmm....I saw Jurassic Park in 35mm back in the day. I don't recall it ever being that dark.

 So did I, and me neither. It's been 22 years, though. But the recently released 35mm scan from guys here on OT revealed that.

FrankT said:

What am I looking at? All I see are tinypic signs.

 It was me, I was updating the images.

AntcuFaalb said:

DrDre said:

I've developed a new method, called parameter free color correction

That's awesome, Dre! How does it work? Can you try it with our 16mm SotS scan?

Also, I'll make sure to try the LUT tonight. I had an unexpectedly-busy weekend.

 It's actually pretty simple. You first go to the appropriate color space for film, namely magenta, yellow, and cyan. You then reverse the color order, take the log10, and shift the average colors, and standard deviation to an appropriate value defined by a set of frames of the shifted print. 

Sure, just post a few frames, and then we'll see what we get.

The version of the Jurassic Park scan that was released is a quick-and-dirty rough version. I believe the LUT was set to adjust black levels to pure black. The digital video codecs we use still have a narrower dynamic range than film (even at 0-255), and film doesn't actually project black as absolutely pure black (even, I assume, on stuff like IB Tech and silver retention that I've heard have deeper blacks than other prints). So it probably wasn't that dark in theaters. Or at least, you could probably see what was going on better than in those images.

PDB, DoomBot, are either of you here? I know this thread isn't about the JP preservation, but can you weigh in? Is there lost shadow detail compared to the flat scan?

I am also interested in how the colors of Jurassic park are meant to be.

Although the quality is not great does this trailer give any indication to the original colors? https://www.youtube.com/watch?v=Bim7RtKXv90

Well, maybe it's not supposed to be that dark. But it does give the scene a creepy mood that I like better and helps make the T-Rex more real. When brighten, you see just by looking at his feet that it's fake.

Anyway, when starting with the 2D Blu-ray :

... and matching it to the 3D Blu-ray :

... I obtain this :

So it is possible to have a Jurassic Park with better colors and not DNRed like hell. It's still darker than the 2D, but less than the 35mm scan... and unfortunately the feet reveal the phony business.

Here's what the new algorithm predicts for the two frames that were discussed at length a while ago: