one bit transparency

[bitrat]

(11-05-2022, 09:16 AM)denzjos Wrote: Image / Mode / Indexed (Use black and white (1-bit) palette)

Thanks denzjos.  That's a good idea to add the alpha then convert mode.  I thought it solved the problem, but unfortunately it doesn't (quite) work...

Here's what I do (that doesn't work).

1. create a black and white image with redundant bit width (RGB or grayscale)
   
2. add a layer mask
   
3. copy bw image to layer mask
   
4. fill image layer with solid black
   
5. convert to 1-bit indexed image mode [ Image | Mode | ...Indexed -> Use black and white (1-bit) palette ]
   

Unfortunately, although I ask for a 1-bit palette, the result is an antialiased 8-bit palette.  (I'd call this a bug, because I'm not prevented from selecting the 1-bit palette.)

What I want is black+transparent, rather than black+white.  I'm reasonably sure there are other ways to accomplish this.  Unless it's actually impossible to do with PNG, I could probably write a C program to get wiw in 5 minutes.  It's effectively a black sprite and I'm fairly sure it's possible in most icon file formats.

I'd also like to solve the associated Inkscape issue so, if any Inkscape aficionados out there can help, that would also be appreciated!

Cheers!