how can I sharpen through an alpha channel like in Photoshop?

[Tudor “ted” jelescu]

One way of doing it:
You can duplicate your layer, apply find edges and precomp. Use this as a Track Matte for a Adjustment layer that you create on top of the bottom video layer. Apply Sharpen on the Adjustment layer.

I am not sure though that this will give you better results than just applying Sharpen directly to the video layer.

Tudor “Ted” Jelescu
Senior VFX Artist

[Walter Soyka]

You might like Darby Edelen’s excellent technique for high pass in Ae:

https://forums.creativecow.net/readpost/2/931967

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog – What I’m thinking when my workstation’s thinking
Creative Cow Forum Host: Live & Stage Events

[Darby Edelen]

[Walter Soyka] “You might like Darby Edelen’s excellent technique for high pass in Ae:”

I’ve changed my wicked ways 🙂 I usually just use Unsharp Mask now since it’s virtually the same result but faster to apply.

You can apply Stylize > Find Edges to a copy of your footage and use this as a luma matte for another copy of your footage with Unsharp Mask applied to follow along with the tutorial you linked to (applying the appropriate blurs and levels adjustments).

However, I’d just apply Unsharp Mask and use the Threshold parameter to reduce the sharpening in lower contrast areas (basically what the Find Edges operation would do).

Again, if you want to follow the tutorial directly you’d set the Unsharp Mask copy of your footage to the Lighten blend mode.

Darby Edelen

[Jon Iverson]

Problem solved. Created an action in Photoshop to do what I wanted to, then used Virtual Dub to convert the video to an image sequence, allowed PS to do the custom sharpening, and then Virtual Dub to reassemble the images back into the video.

[Darby Edelen]

[Jon Iverson] “Problem solved. Created an action in Photoshop to do what I wanted to, then used Virtual Dub to convert the video to an image sequence, allowed PS to do the custom sharpening, and then Virtual Dub to reassemble the images back into the video.”

Alrighty, but you could’ve done everything that’s in that tutorial directly inside of After Effects. It’d render faster and be much more straight forward as well.

Darby Edelen