Show HN: Painterly – Turn pictures into digital paintings without generative AI

Painterly is an application that "paints" input images stroke by stroke to produce digital paintings. GenAI is not used in any part of the production pipeline.

There is a free demo available under Releases on the GitHub repo.

Let me know what you think!

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flinkerflitzer a day ago | parent | next [-]

Here is some footage of the program for those interested: https://www.youtube.com/watch?v=9iWu4ArbD5Q

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verdverm a day ago | parent | prev [-]

I'm curious about the greedy algorithm vs something like compressed sensing. Can you expand on the algo choice and how it works?

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flinkerflitzer a day ago | parent [-]

Sure!

The brush stroke accept/reject algorithm looks at the axis-aligned bounding box that surrounds each candidate brush stroke's affected area. It calculates the cumulative pixel color similarity between the input image and the painting over this area, before and after the candidate brush stroke.

Pixel color similarity is the sum of the absolute difference of each RGB color channel divided by 3.

The candidate brush stroke is accepted and kept by the painting if and only if it represents an improvement in similarity over its affected area AABB.

	▲	verdverm a day ago \| parent [-]
		Thanks for more details. I've been getting into street photography lately and wanted to make renders of the images using old-school image processing techniques. There are a ton of them out there that could mix-n-match for some really cool effects.