How to select solid background in Adobe Premiere?

[João23738580ajt9]

Hi there!

I rendered an animation in 3ds Max + Corona and, besides the LightMix render, I also ended up with the CMasking_WireColor. My plan is to whiten the background in Premiere, while maintaining a soft shadow. Unfortunately, using the Corona Shadow Catcher Material didn't give me the results I wanted.

Does anybody knows how to select the background color in the CMasking_WireColor video, in order to select the Interactive_LightMix background video (the main one, with the textures) and lighten it up (similar to what is possible in Photoshop)?

[Ishan Y]

Hi João,

Welcome to the Premiere Pro community. If I understand your question correctly, you want to use CMasking_WireColor to remove the background from Interactive_LightMix. To do so,

1. Apply the Luma Key effect on CMasking_WireColor and set the Cutoff to 50%.

2. Apply Track Matte Key on Interactive_LightMix. Set the Matte to Video 2 and enable Reverse.

(To enable the transparency grid, select the wrench button on the Program panel and select "Transparency Grid")

In case I misunderstood your question, could you please share more details?

Thanks,

Ishan

Please tag me (@) in your replies so that it notifies me and helps me respond promptly.

[João23738580ajt9]

Hi Ishan,

Your method is indeed perfect to remove the background, thanks.

However, Since CMasking_WireColor doesn't have the furniture shadow, I'd like to select the pink background of CMasking_WireColor, and use that selection to brighten up the white background of the Interactive_LightMix. I know it will also make the shadows less intense, but that's a drawback I can live with.

Can you help me with this?

[João23738580ajt9]

Sorry, I forgot to tag you, @Ishan Y . And for some reason, I'm unable to edit me reply...

[Ishan Y]

Try this:

Stack Interactive_LightMix on top of CMasking_WireColor.

Select Interactive_LightMix, go to the Effect Controls Panel, and set the Blend Mode to Luminosity (you can choose Multiply too. Luminosity will lighten the pink background color, and Multiply will darken it.)

You'll have to add the keyed-out clips on top of these clips. 

[João23738580ajt9]

I did exactly what you said, @Ishan Y , and I got the same results as you. However, I don't want to have a pink background. My objective is to select the pink background (since it is a solid color, it's easy to select it), and use that selection to make the white backround even whiter (with levels, curves, some other tool...).

The goal is to end up with a white background (or as close to it), instead of a grey one.

[Ishan Y · Accepted solution]

I see. You can do that by following the steps in my initial reply and adding another clip of Interactive_LightMix at the bottom. Then, select the bottom clip and go to the Lumetri Panel to make the color adjustments (top menu bar, Window > Lumetri Color). I have attached a screenshot where I have lightened the background color by increasing the Whites slider in the Lumetri Panel.

[João23738580ajt9]

It worked! Thank you so much for your patience.

[João23738580ajt9]

Sorry for bothering you again @Ishan Y .

I just noticed that, when I increase the whites, there's a subtle aliasing in the border of the selected object. Is it possible to slightly blur the edge of the selection to avoid this?

[Ishan Y]

That's not a problem! I can't tell if this works for me. Please give it a try and see if this method helps.

Nest the clips for the keyed-out object and apply the Edge Feather effect on the nested sequence. (select clips, right-click, Nest)

After Effects has an effect called Simple Choker that makes fixing these issues very easy. If you have it installed, you can try importing this sequence into After Effects (in case the Edge Feather effect doesn't work). 

[João23738580ajt9]

Thank you again for your help, @Ishan Y 

I'm going on vacation right now; however, as soon as I'm home again, I'll test your methods and I'll ket you know if they worked.

[Ishan Y]

No worries!