logo Sign In

nightstalkerpoet

User Group
Members
Join date
25-Oct-2010
Last activity
6-Jul-2025
Posts
1,111

Post History

Post
#789561
Topic
Color matching and prediction: color correction tool v1.3 released!
Time

So just to clarify,  the single frame technique corrects all resulting frames in a single color space? 

If so, is there a chance to implement a third option, where the original image is corrected, saved, and then the multiple color space model analyzes the source image and uses the new image as the reference? I'm just thinking that some images in the film may require a little more force to push the correction. Or is that assumption incorrect?

Post
#789451
Topic
Color matching and prediction: color correction tool v1.3 released!
Time

I'm finding damn good results with using Gimp to color match the initial bluray frame to the reference, then using Color Match to predict references by building a profile from the initial frame and the Gimp frame. Quite contrasty but a decent first attempt.

http://screenshotcomparison.com/comparison/143241

http://screenshotcomparison.com/comparison/143242

A frame from the other scene using this prediction:

.

.

.

.

My process - 

Install Gimp 2

Go HERE and grab the Histogram Matching plugin

THIS explains how to install the script.

Now...

1.

Open your two images -original and reference- in seperate gimp windows (not as layers).

In your reference frame, bring up Histogram Match in Colours->Map->Match Histogram

Set source to your original frame. Make sure the only box checked is Sample Full Size, and that both adjustments are set to 0. 

In "Channels to Use" select LAB - Preserve Luma.

Hit okay, let complete.

2.

Now switch to your original frame window leaving the other still open, and bring Match Histogram up again here.

Make sure the source is set to the reference frame, and the "Channels to use" is set to plain LAB - other settings remain same as before.

Hit okay, let complete.

3. 

Switch back to the reference frame window and Edit>Undo Match Histogram to return to original color.

4.

Finally switch back to the ORIGINAL frame window, bring up Match Histogram, set source to REFERENCE frame and "Channels to use" as YCbCr.

(in some cases, YCbCr will oversaturate the resulting image. In those instances, RGB or LAB in the final step may work better.)

Hit okay, let complete.

5.

Export and save. This is now your reference image in DrDre Color Match, and the original is your test image. Build your color model from these.

Post
#789422
Topic
Color matching and prediction: color correction tool v1.3 released!
Time

I've been curious about average film histograms for color correction.

Something like getting the color histogram from every frame of a target, and averaging them together. Then doing the same for a reference.

Then running a two pass color correction similar to encoding, where the first pass goes through and finds the best way to compress the chroma to "fit" the reference, and the second pass tightens that a little and actually does the color correction shift on each frame.

Not sure if that would work, but theoretically seems like a good way to do a preparation color correction to remove any tinting done across the whole film.

Post
#787654
Topic
Info & Service: Audio and/or video captures offered... anyone interested?!?
Time

Yeah, yeah... necromancy. 

I'm curious, have you managed to get your hands on a MUSE decoder at all?

I'm really curious if SD Laserdiscs, fed to a MUSE decoder, and captured over Component cables might provide better quality than stand-alone LD players over S-Video.

If they were - I'd request new captures of everything :P

Post
#785711
Topic
Help: looking for... German & Hungarian digital TV-Rips of the original 1999 theatrical version of "TPM" and the original 1997 Special Editions of the Trilogy!
Time

Apparently this channel runs a SW marathon every September. Anyone up to trying to capture and see if it's theatrical? I know OP said they switched to DVD sourced, but there's always hope for a happy accident ;)

http://www.fernsehserien.de/star-wars/folgen/episode-i-die-dunkle-bedrohung-661794

Post
#785675
Topic
TPM 1080p Theatrical Preservation (a WIP)
Time

@Alexrd That was me. I only asked because I hadn't seen that shot in that high of quality before and was curious of your source.

Apparently I need to feast my eyes on the blu shot :P

@Valeyard this is a VERY quick and dirty comparison of the Sebulba scene (gimp lanczos3 upscale of GPVOD vs your lossless upscale of the extras dvd) 

http://screenshotcomparison.com/comparison/139232

I figure if a rough scaling can put them that close, your scaling script will probably work wonders.

Post
#785664
Topic
Color matching and prediction: color correction tool v1.3 released!
Time

I'd just drop the brightness (or contrast - hard to tell which sometimes) and saturation down a tiny bit each, otherwise these look stellar.

http://screenshotcomparison.com/comparison/139222

http://screenshotcomparison.com/comparison/139223

http://screenshotcomparison.com/comparison/139224

http://screenshotcomparison.com/comparison/139226

The last one may be slightly too desaturated, but I always felt that SW looked more "authentic" that way, and Carrie Fisher's face was always rather pale.