Quality Loss after re-opening

[Ofnuts]

(06-17-2023, 09:30 PM)BushidoVR Wrote:

(06-17-2023, 09:24 PM)Ofnuts Wrote: Are the lines on transparent layers or painted directly on a background?

They are on transparent layers.

My only explanation for this is that your layer transparency got thresholded, and if this happened in all layers my only explanation is that you set the image to color-indexed mode, knowingly or not, because in color-indexed mode, to conform to GIF, the opacity of layers is binary.

You can restore most pf the antialiasing bydoing a poor man's supersampling.

• Scale up 4 times using Linear interpolation, which is going to produce lines with fuzzy borders
  
• Threshold the alpha (at 50%)
  
• Scale down to original size using NoHalo interpolation
  

So instance starting with this smooth line:

   

We "accidentally" threshold it:

   

And after applying the technique above you get:

   

For a closer look the difference of the thresholded and restored image with the initial image:

With thresholded:

   

With restored: