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Home: Video University Forums: Digital Photography for Videographers:
PS: How to select only the bright areas?

Brackish
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Jan 6, 2008, 2:16 PM

Post #1 of 4 (457 views)
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PS: How to select only the bright areas?	Can't Post

You know how brightness levels go from 0 (blackest) to
255 (brightest)? I want to select all levels in a photo above say 200 or
so. It would be nice if there was a slider so that I could select
just the cutoff point in brightness that I want by eyeing the
photo up as I'm moving the slider.

Here's basically what I want to do:

1. Have a background image on layer 1.
2. Above it on layer 2 have an image where I remove
all the brightest areas (above 200 or so) and have this
layer be a mask so that I can have all the brightest
areas to show through to the background on layer 1.
So, somehow I'd need to make the bright areas on layer
2 be like they were painted with a black brush so that
they allow the layer 1 background to show through.

Anyone could get me started in the right direction?

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"We'll always show up at the wedding with a gift bag for the bride. Inside we have these incredible fuzzy slippers in the teal of our branding."

Postal Boy
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Jan 6, 2008, 8:29 PM

Post #2 of 4 (439 views)
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Re: [Brackish] PS: How to select only the bright areas? [In reply to]	Can't Post

I believe that adding a "threshold" adjustment layer and cranking it up will allow you to do that, then copy the screen and apply that as a layer mask to the layer you want to have modified...then just delete the threshold adjustment layer when you are done with it. Not sure if it will do exactly what you want, but that is where I would start.

-Postal

Brackish
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Jan 7, 2008, 11:35 AM

Post #3 of 4 (409 views)
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Re: [Postal Boy] PS: How to select only the bright areas? [In reply to]	Can't Post

Okay thanks, Postal.

I was actually thinking "threshold" might be where to
start because there is that controller in video editing software.

Now I just have to find where threshold is located. LOL.

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"We'll always show up at the wedding with a gift bag for the bride. Inside we have these incredible fuzzy slippers in the teal of our branding."

Postal Boy
Veteran

Jan 7, 2008, 3:05 PM

Post #4 of 4 (398 views)
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Re: [Brackish] PS: How to select only the bright areas? [In reply to]	Can't Post

What version of PS are you using? If you are using CS (I have CS3), then at the bottom of the layers pallett there are options to add "adjustment" layers...Threshold is one of the ones you can add to a layer - adjustment layers are non-destructive so you can add them, remove them, adjust them, etc...and they (by default) only affect the layers below where you apply it. Then, if you want, you can make it affect only the layer that is right under it and none of the others. They are pretty handy.

=Postal