Flood Select Blending

[DiVille]

Hi guys, 

Another basic question but I'm really enjoying using Affinity so far. Again, posting not because I can't be bothered to search, but because I don't know what to search for...

I'm trying to cut sections out of a black and white image, so have tried using the Flood Select tool. The issue that's creating is when I try to flood fill the cut out area, I have the various shades between black and white leaving ugly edges. Is there a simple way to combat this?

Thanks!

[Aad Slingerland]

Did you happen to specify Refine Selection, Feather? This will cause a selection to 'fade' on the border.

[DiVille]

Feather seems to fix and make the problem worse at the same time. I lose the bad blending but also the crisp lines. I'm looking to get the white to be transparent, the only details are black, but I'd like to retain the blending. Would replacing the white for alpha work? No idea how I would do that though.

[DiVille]

I wonder if I am attacking this problem the wrong way.

Is it possible to select every shade of white between 255 255 255 and 1 1 1 and change them to varying degrees of alpha, instead of white?

[Alfred]

I think you must have meant to type ‘grey’ or ‘gray’ rather than ‘white’: RGB (255,255,255) is white but RGB (1,1,1) is nearly black. Anyway, the ‘Rasterize to Mask’ command (on the Layer menu) will do what you’re asking for.

[DiVille]

10 minutes ago, Alfred said:

I think you must have meant to type ‘grey’ or ‘gray’ rather than ‘white’: RGB (255,255,255) is white but RGB (1,1,1) is nearly black. Anyway, the ‘Rasterize to Mask’ command (on the Layer menu) will do what you’re asking for.

You were right on both counts, and it would be grey for me! Thank you for your help.

Rasterize to Mask did exactly what I needed, but what I don't know, is why. What did rasterizing have to do with taking the white out of the image? Of course I had to invert the colours before I did it, but I do like to understand what is happening when I'm doing things.

[Alfred]

12 hours ago, DiVille said:

Rasterize to Mask did exactly what I needed, but what I don't know, is why.

I’m afraid I don’t know for certain. My guess is that this is just the developers’ way of telling the user that the resultant mask will be raster rather than vector.

12 hours ago, DiVille said:

Of course I had to invert the colours before I did it

Although that seemed the most likely scenario I didn’t like to assume that was what you wanted, but I should at least have mentioned it! Apologies for the oversight.