VPX15 Colour Correction Problem - try to remove bluish tint

browj2 wrote on 9/24/2023, 11:04 AM

Hi,

Here is something to play with.

I have some Super8 film with parts that go from normal colour to a very bluish tint and back again a couple of times. Try as I might, I was not successful in even getting close.

Here are the images in Dropbox:

https://www.dropbox.com/t/bFfd6Dzj5zFUbIbv

Below are the images and the corresponding meters:

Bad colour:

Correct colour:

There are no effects on the above images other than Speed.

I tried unsuccessfully with Shot match (but did get a bit better), playing with the Color Wheel, adjusting the gradation curves and some third party effects.

Here is one attempt using Color and Color Correction. The Vector Scope and RGB parade look better, but no colour. A bit earlier in the clip I can see some of the colours but in this one, there is very little:

Please let me know if you find something that improves the image to get closer to the correct one.

Thanks,

John CB

Comments

johnebaker wrote on 9/24/2023, 12:42 PM

@browj2

Hi John

. . . . I was not successful in even getting close . . . .

I am not surprised - the blue image has 0 - 6 units, on a scale of 0 - 255, of red which, IMHO, is not enough to get anywhere a decent result like the Correct colour image, there is not enough red anywhere to determine where it should be 'lifted'.

Personally if the video is essential, I would monochrome or sepia tone it.

John EB

CubeAce wrote on 9/24/2023, 2:00 PM

@browj2 I'm going to have to agree with John. I don't know if I'm even getting close to correct.

And that's with Photoshop and about eight filter layers.

browj2 wrote on 9/25/2023, 9:42 AM

@johnebaker @CubeAce

Gentlemen,

Thanks for taking a stab at it.

Ray, in your image, the blue feathers on the dancer should be red.

I did some further testing. I found some adjustments to red and blue gradation curves along with some tweaking in Color and Temperature gave a better result - got rid of the bluish tint and was closer to the other shot. The frame that I showed was amongst the worst of the bluish part so other frames are even better.

NB ColorFast 2 also gave better results. I have yet to apply my tests to the original footage.

The video is not essential, but an improvement would may it less jarring to the eye; getting rid of most of the blue - warming up the image - seems to do it.

I'll post the final result.

From memory, this was the lion dance and was somewhat surreal. The continuing acrobatics of the dancer, about 10-12 years old, depended on the amount of money placed in front of him.

Thanks again,

John CB

CubeAce wrote on 9/25/2023, 10:28 AM

@browj2

Hi John

I did wonder about the feathers and did a few variants, but again with Photoshop. Not sure how it could be done with VPX.

It is possible if you get a good tonal B&W image to then put a red, a green, and then blue filter to recreate a colour image. I will give that a go.

Ray.

browj2 wrote on 9/25/2023, 1:06 PM

@CubeAce

Hi Ray,

The 2 images that you show are from the good image, it's the other one, the bluish one, that needs fixing.

John CB

CubeAce wrote on 9/25/2023, 2:38 PM

@browj2

Hi John.

You misunderstand me. Those were my second and third attempts. What I meant was, if it were possible to get a good contrast black and white image from the blue one it may have been possible to colourize from that black and white image.

I have tried but there is not enough tonal graduation or resolution in the image for it to work. Red is completely blown and green is close to total blowout. It's similar to the work I do on old B&W family photos. I can't currently find one as it's on one of my other archive drives and I forget the year I did them but I cropped this from a collage I put onto Flickr of my grandfather working in what was then, the Ghana Gold Coast.

The colours are always a bit washed out in that process but I think it adds to the look.

Ray.