I know there are ways to do this. I have some images that are black on white silhouettes that I need to use in my footage. I need the black silhouettes to be alphas and get rid of (key out?) the white. I know how to delete the white background in photoshop and then send it over, but it is very time consuming. Does anyone have any tips on how to do this quickly within after effects?
The left side of the image is what I have to work with, the right is the desired effect. What is a quick way to do this from within after effects?
Thank you for the response Ridley. I think I got thrown off because when I tried to use Keylight, it wouldn't work. I just tried it again with keylight and still had no luck. Color Key did work however, so thanks. I feel dumb that I didn't try it before. I guess I figured if it wouldn't work with Keylight, then...
Some of the Key effects use differences in the color channels to achieve the key (Keylight, Color Difference Key, etc.) and these won't work in this case. You could use some of the other Key effects but you don't really need to.
Since you have what appears to be a black/white image already you basically have a matte, you just need to shift that matte from the RGB into the Alpha channel. You could do this in several ways:
1) Create a new black solid below the image, set it to use the top image as a Luma Inverted Track Matte.
2) Create a new black solid, apply the Set Matte effect, point it to the image and take matte from Luminance.
3) Apply the Shift Channels effect to the image and set Take Alpha From to Luminance.