Separate YUV channel images from a std image
by Zafer Mustafa
on
Jul 15, 2008 at 7:39:29 pm
I'm almost embarrassed to ask this as I think I 'should' be able to figure this out, but i'm stumped.
I need to find a way of creating separate luminance and chrominance x2 images from a group std images in my possession. Luminance, i'm okay with, but i'm having trouble figuring out how to create the two chrominance channel images.
the particular formula i need to use is:
1: (B - Y) for one, and
2: (R - Y) for the other.
I'm sad to say i don't know how to go about accomplishing this in AE.
Any thoughts/leads would be unbelievably welcome! Thanks so much!
Re: Separate YUV channel images from a std image by Darby Edelen on Jul 15, 2008 at 8:14:08 pm
The Channels > Channel Combiner effect will allow you to translate the RGB channels to YUV channels. However, it doesn't follow your formula:
[Zafer Mustafa]"1: (B - Y) for one, and
2: (R - Y) for the other. "
I wonder if that's really what you want to do, seeing as the luma values are sure to be greater than the majority of the values in either the Red or Blue channels.
Re: Separate YUV channel images from a std image by Zafer Mustafa on Jul 15, 2008 at 8:35:41 pm
Darby, thanks for your reply...you're right, those 'equations' are not literally true.
Regardless, thanks for the info on the Channel combiner...do you know how to view each one of the channels individually though? so once you've converted to YUV, how to view the Y, U, and V channels independently???
Re: Separate YUV channel images from a std image by Darby Edelen on Jul 15, 2008 at 11:08:12 pm
[Zafer Mustafa]"so once you've converted to YUV, how to view the Y, U, and V channels independently???"
After conversion:
R = Y
G = U
B = V
So you can use Shift Channels or another of the Channel effects to set the layer to one of the YUV components, or use opt-1, 2 or 3 to look at the Y, U or V (alt-1, 2, or 3 on PC).
Darby Edelen Lead Designer Left Coast Digital Santa Cruz, CA
