Original subtitles

In this clip we're going to take a look at restoring lost noise and luminance.

So, let's take a look at our script.

So,

the first thing we're going to take a look at is our original

image and we are going to pull a de-spill,

so here is our de-spilled image and we're going to focus on

the bottom left-hand corner over here.

Now,

the de-spill workflow will actually take away information

practically from the luminance and we're going to see what

that looks like in just a moment.

So, let's isolate that loss of luminance and again,

I call it lost noise because it looks like noise and it's going to make our

image look quite crunchy for lack of a better description.

So, this is where the lost information is.

It's primarily on the back of our actor's head and down

here at the bottom of the chair and we can reintroduce it

back to our de-spilled image,

so let's just zoom in here and we're going to compare it

against the original de-spilled plate, so this is like the four,

again, here's the crunchiness that we were talking about,

looks very,

very noisy and it's not very smooth or even across our image

and there are stored information here, so again,

nice and smooth,

no crunchiness and the noise over here and we've restored that information.

Now, just a reminder that it does change that backing region color,

so you will want to potentially color correct it separately much like

we've reviewed in our last module but the main thing is is that it's

adding back that luminosity that we had lost so that we have the best

quality image possible for our final composite.

So, now let's take a look at what that looks like in our workflow.

So, if you're still following along from our last module,

everything from our last module is in the blue backdrop and

the new items are over here in the teal.

So,

we're going to take our footage of our dancing little girl

here and we're going to pull a de-spill,

doesn't matter how,

just any sort of de-spill and we're going to do a minus operator,

so the minus operator's going to be what's to determine

the difference between the two elements,

so here's the D to spill,

here is the original image and the difference between the

two of them and here is just an exaggerated portion of our

luminance that's been lost, we're going to see it mostly in the beads,

a little bit in her hair.

We're going to de-saturate it because we don't want to

be adding back any of the green, just the luminosity,

remember, luminosity is in a black-and-white image.

We're going to then plus it back over top of our plate

and let's just take a look at her hair.

Remember, that's where that information was mostly lost,

so this was the de-spill and the luminosity added back

to her hair and it's nice in here.

Sometimes it's very subtle, it is quite subtle,

so that's before and after, so it's quite subtle but again,

a little bit of information goes a long way.

So, now let's take a look at our blue screen.

So, here is our blue screen preprocessed image,

it's just a little corner fraction of it for us to focus

on and we're going to pull a de-spill, do a minus operator here,

de-saturate it and plus it back over top of the plate.

So, let's take a look where that luminosity's been lost.

Again, it exaggerated.

Just reference here, primarily in the back of the headrest,

a little bit here in the dash and on her hands,

so let's compare it, so here is the de-spill,

let's turn up our LUT so we can see those details,

so this is before and after and again,

it's pretty subtle but there's a little bit of change there,

just enough to add back that detail.

Now,

one last thing that I did want to add is if you wanted to color

correct this backing region through this process,

is that you can add a color correction tool here after the de-saturations.

We can add more information here.

Be careful,

you don't want to push it too far because you start to

add that information back to the image, so you would have to isolate it,

it's just the backing region but it can add a little

bit more information back there.

Just don't push that color correction too,

too far because it will just start to destroy our foreground image.

So, in this particular clip,

we took a look at adding back the luminosity that was

lost during the de-spill process.