How to smooth areas of color together without anti-aliasing?

[dracho]

Hi, I'm creating a template and each color that's in the .png file must match a string in a config file.  Therefore, only colors I specify can be included in the .png file.

 

I drew some shapes, then resized the whole image by 500%.  As you can guess, huge blocky jaggies are everywhere, as seen here:  https://imgur.com/LQg1VvX

 

I believe I tried all the filters, and Dent came closest to what I need, but it introduced "random" colors by anti-aliasing, as seen here: https://imgur.com/reCsjsN

 

I am looking to apply a smoothing filter to this whole map, only using the colors that are currently included.  (Here's the full map if you were curious: https://imgur.com/4n3Akjk )

 

Thanks much!

Edited May 3, 2018 by dracho
added links

[toe_head2001]

One option would be to use the Selective Palette plugin.

 

[MJW]

A plugin that might me useful for this is Recolor Using Palette.

 

A trick I tried that seemed to have potential is to  Gaussian blur the image by about eight pixels, enlarge it, then replace the pixels in the enlarged image with the selected colors using Recolor Using Palette or a similar plugin. Sometimes there are regions where two colors meet that get that wrong color. Those can be selected with the Magic Wand (with a low tolerance) and filled with the correct color, or filled with the Paint Bucket.

 

I only tried it fro a small example, so I don't know if it's practical for a full image.

 

EDIT: After a quick try with the full map, I doubt my idea is very useful. An approach that might be worth a shot is to vectorize the map with InkScape.

[dracho]

6 hours ago, toe_head2001 said:

One option would be to use the Selective Palette plugin.

 

This sounds promising, "allow the user to build up a list of colours, and then it converts each pixel in the image to the closest colour on the list."

 

However, there isn't a version for 4.0.21.  Must I downgrade paint.net in order to use this?  Thanks.

[null54]

30 minutes ago, dracho said:

However, there isn't a version for 4.0.21.  Must I downgrade paint.net in order to use this?

 

The download for Paint.NET 3.5.4 works in 4.0.21.

[dracho]

21 minutes ago, null54 said:

 

The download for Paint.NET 3.5.4 works in 4.0.21.

Are you sure about that?  I've tried both, and neither work.  Perhaps I'll try an older 32-bit version of paint.net...

[null54]

43 minutes ago, dracho said:

Are you sure about that? 

 

Yes, I tested it before posting the reply.

 

Did you place all 3 files in the Effects folder?

[dracho]

11 minutes ago, null54 said:

 

Yes, I tested it before posting the reply.

 

Did you place all 3 files in the Effects folder?

Yes.  Here's a crashlog:  https://paste.ubuntu.com/p/dgWtNwkmQT/

 

Err... that crash only happens when I select Effects Lab, which I thought was the menu the new plugin added, but apparently there are more to choose from in the list of effects.  I will see if I have any luck with them.

 

OK, I found the Selective Palette dialog.  It seems like this might work, but I guess I first need to save a palette that includes only the colors in my current .png file.  Once I figure that out, I should be able to import that palette into Selective Palette and... cross that bridge when I get to it.  Thanks.

Edited May 3, 2018 by dracho

[dracho]

Unfortunately I don't think Selective Palette is going to work for me.

 

Say I have two biomes (two different colors) next to each other.  One is dark green and one is light green.  Inevitably there will be some medium green pixels after I apply the effects.  I could eliminate the medium green by using Selective Palette but medium green is actually a valid color in another part of the map.  I don't want a large biome next to another large biome with a minuscule amount of third biome between them.

 

There are 187 biomes, and I don't think I can ever be assured that each pixel is perfect via this method.

 

I just really need a smoothing filter that doesn't introduce new colors...