Removing alpha channels from a layer?

[xuvvy]

Hello,

what would be the best way to remove alpha channel pixels from a layer or make them fully opaque?

In case I'm not making sense, here's an example: I add some red background and make a stroke with the brush over it with a green color, there's going to be red pixels of the background, green pixels of the brush and pixels that are green with alpha channel - how could I remove those with alpha channel or make them fully opaque?

Both GIMP and Photoshop have ways of doing this for whole document, layer or selection, I'm curious how one would do this in Affinity Photo, or even Affinity Designer. I could provide an example if needed.

Thanks!

[telemax]

Select your stroke brush layer, 
Channels > Pixel Alpha > Fill

[xuvvy]

That would work in GIMP or Photoshop but the end result in Affinity Photo is, well, this:


and I cannot figure out why.

I would also prefer if I could find a way to maybe remove those alpha pixels rather than fill them with an opaque color, but either can work, I guess.

EDIT: Example in GIMP below.

Edited December 10, 2020 by xuvvy
Added GIMP example

[telemax]

[xuvvy]

Ah, that makes a lot of sense, didn't think of that. Thanks!

[Dazmondo77]

I always find using blend ranges is really quick and easy:

[xuvvy]

Now that I've tried it a few times, both techniques almost work. The issue is that alpha-channel pixels still persist, while I would like all alpha channel pixels to either be removed or turned fully opaque and I haven't yet found a good way of doing so in Affinity Photo. I've found the 'solution', though, it's at the bottom.

In your example as well, @telemax, most transparent pixels are removed, but not all.

There is no denying that the latter is cleaner, less alpha pixels, but there's still alpha pixels for some reason and I cannot figure out why. Here is zoomed in:


The solution to this, I found, is to just use the fill tool on the pixel layer with the mask layer being nested.


If anyone has any simpler, better or cleaner solution, I'm all ears! 

Edited December 10, 2020 by xuvvy

[telemax]

Maybe it's a little easier:

[lepr]

Here's a collection of three macros to simplify your workflow: Alpha utilities.afmacros

With the target Pixel object selected, run either "Clear partial alpha" or "Fill partial alpha".

("Fill alpha of selected pixels" is required by "Fill partial alpha", so do not delete it.)

[Dazmondo77]

15 hours ago, xuvvy said:

The issue is that alpha-channel pixels still persist

This is really easy to do using blend ranges: