Maybe it will be overkill for flags, but you can try with dithering algorithms, where you can select which color you want to keep: Https://ditherit.com/ Https://github.com/noopkat/floyd-steinberg. Source: over 1 year ago

ImageMagick can do anything, but it's a commandline program. There may be some websites that dither images for you - https://ditherit.com/ is one. (I also wrote a program years ago that is excellent at color reduction and dithering, but it's not currently usable.). Source: over 1 year ago

It’s called dithering. Instead of using many different colors you just choose a few and make the best of it. With using six colors (red, green, blue, yellow, white, black) any color can be matched. You can try it out with this tool: https://ditherit.com/. Source: almost 2 years ago

I used https://pixelartselfie.com/en. I later found https://ditherit.com/ which offers more features so I’ll probably do more works. Source: almost 2 years ago

Check this website: https://ditherit.com/. Source: almost 2 years ago

If you're into video game dev, then PixiJS is something you need to know about. It's a HTML5 game engine that provides a lightweight 2D library across all devices. This latest update has a new package structure, custom builds, graphics API overhaul, and lots more. You can read about all these changes in the PixiJS Migration Guide. Also big congrats to PixiJS for being part of the open source community for ten... - Source: dev.to / about 2 months ago

I would need a renderer to display the graphics of my calculations on the "backend". After some research I think pixijs which is written in TS could be a great tool. Source: about 1 year ago

And if that seems to up your alley you could look into Javascript game/renderer frameworks. They have 2D engines like https://github.com/photonstorm/phaser or https://github.com/pixijs/pixijs . Or my personal choice A-Frame which is a 3D, AR and VR engine (XR) https://github.com/aframevr/ . Source: over 1 year ago

This has a high risk of being confused with pixi.js: https://github.com/pixijs/pixijs. - Source: Hacker News / over 2 years ago

WebGL, I hear, has a similar API to OpenGL. (Also, WebGPU is coming at some point.) Or, you could use a thin library that handles the WebGL drawing of sprites for you. I prefer that option over using a full game engine: I find it's better to only include dependencies when they become necessary. I recently tried a web rendering library called PixiJS, and it seemed like a pretty clean and nice-sized API, and... Source: almost 3 years ago