Antialias effect intensity

[Hackerman]

Of course I can apply gaussian blur in selections (fuzzy tool selection, then float selection so as not to include colours outside the selection in blurring and after that gaussian blur). Why not? But it would create much better borders if I did it without aa and applying aa afterwards. I really haven't found a program that has a good aa option. I already tried Adobe Photoshop and Illustrator. So I'll try Inkscape next. Are you aware of any program with good aa options (eg selecting algorithm, intensity etc)?

[Ofnuts]

There is no AA option because it doesn't make sese to remove the AA to add it afterwards. If you tell us what you want to do (and not why you want to remove the A , because when you are there you have already taken a wrong turn somewhere), we could suggest better techniques/workflows.

Inkscape and Illustrator are a different kettle of fish: these are vector graphics programs. The AA is re-computed from scratch when the vectors are rendered, so it will always be perfect (and one pixel wide).

[Hackerman]

But I already mentioned that it would be better to import the image without AA so the fuzzy tool will not leave any unselected pixels near borders where AA is applied. To include those pixels I would have to select them one by one, because if I increased the threshold too much, other irrelevant colours would be selected. We know how good color-based tools work if the borders are crystal clear and not anti-aliased or blurred.

So let me redefine my question. Is there any way to get a stronger AA effect (antialiasing algorithm only) than the standard 1 pixel wide on a raster image in GIMP? If not, would you recommend any other software that can accomplish that? Again, antialiasing algorithm on a simple raster image, wider than 1 pixel. Other details are irrelevant with my initial question.

[Ofnuts]

You are still not stating your initial problem, but your intended solution to another problem. You don't need to rebuild AA. If you need this, you did something wrong earlier. The fact that you have trouble finding what you are looking for should be a hint.

[Hackerman]

I want to apply AA to a raster image that doesn't look good with 1px AA! I need more AA! 1pixel AA is unheard of (unless the image has dimensions less than 10 pixels). If you search "png" online, it is rather unlikely that you will find an image with no AA or 1px AA. I have never seen an image with 1px AA. I have a random raster aliased image. Is there any way to apply AA larger than 1px or not? I want a single-word answer please.

[rich2005]

I could answer that with more than a few choice words, but I am too old to be bothered.

Quote:..I have never seen an image with 1px AA

 

I think you are wrong there

Applying a blur will get what you want, but that will degrade the whole image. However you might get 2 pixels (one into the boundary / one out)  from the Gimp plugin g'mic http://www.gmic.eu and the filter wavelet antialias.
This a snippet for before / after comparison from the full size image.

   

Filter looks like this:  https://i.imgur.com/ihfdNXD.jpg

[Ofnuts]

(02-19-2019, 10:35 AM)Hackerman Wrote: I want to apply AA to a raster image that doesn't look good with 1px AA! I need more AA! 1pixel AA is unheard of (unless the image has dimensions less than 10 pixels). If you search "png" online, it is rather unlikely that you will find an image with no AA or 1px AA. I have never seen an image with 1px AA.

Show me where you see more than 1px AA in this image:

   

(02-19-2019, 10:35 AM)Hackerman Wrote: I have a random raster aliased image. Is there any way to apply AA larger than 1px or not? I want a single-word answer please.

No. You can have blurred edges, but this is no longer AA. AA is the frontier between pixels that have the subject color and the pixels that have the background color. In an ideal world, with infinite resolution, this frontier is infinitely small. Since we have to deal with real life pixels there are only 3 possibles cases:

• The pixel is completely inside the border: it assumes the color  of the subject
  
• The pixel it completely outside the border: it assumes the color  of the background
  
• The pixel is straddling the border(*): it assumes a color which is the blend of the two colors, more or less proportionally to the respective areas inside and outside the border for the pixel.
  

(*) Not that this implies that you can't have two (or more) pixels in a direction perpendicular to the border that are straddling an infinitely thin border, so the AA applies to a most one pixel.

This is a zoom of the image above with the path that is the "border". Notice that all pixels that aren't full white or full black are straddling the border.

   

[Hackerman]

In that image, I see 1-3px AA. Not 1px. What GIMP did was add a px between the already existent border and the solid colours. In your image, I see the pure black pixels compose the "old" image and then there are 3 added pixels with descending opacity. Am I wrong? But in my case it needs more AA to look good.

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I installed the plugin but I am unsure of how to continue. I have never used plugins before. How should I proceed?

[rich2005]

Quote:I installed the plugin but I am unsure of how to continue. I have never used plugins before. How should I proceed?

Best I can do for the moment is a short video:

https://youtu.be/AnSlqFIaeFQ duration 2 and a bit minutes

Let me know when you are finished with it, so I can delete it.

[Ofnuts]

(02-19-2019, 05:26 PM)Hackerman Wrote: In that image, I see 1-3px AA. Not 1px. What GIMP did was add a px between the already existent border and the solid colours. In your image, I see the pure black pixels compose the "old" image and then there are 3 added pixels with descending opacity. Am I wrong?

Where (pixel coordinates)?