The maximum color quantization you can do on this image without huge information errors is something like:
- 1x yellow-brown for stars / streamers / shorts / socks
- 1x brown for tree base (though it might be better to remove the base to save a color)
- 1x red for baubles / hat / sweater / shoes
- 1x green for tree
- 1x blue for hair (potentially you could merge the tree color if you want to really push it)
- 1x skin tone for skin
- 1x pink for mouth
- 1x black for lines
- 1x light yellow for background
Which is 9 total colors. This would also require living with aliased text ( c r u n c h y ), since it would be data-expensive to add extra shades of gray. At that point you’re no longer making a low-quality copy of the original - you’d basically be making a pixel art version of it since you can’t afford any colors for anti-aliasing and gradients.
Here’s an example PNG with 9 unique colors and some pretty simple patterns without huge information density: https://files.catbox.moe/bj0acl.png
Even that’s 1,847 bytes! (i.e., basically 2KB)
Responding to Valmond’s comment got me thinking about doing some more pre-processing to assist the compression, so here are three more 1KB versions which I think are slightly improved: