Intriguing and nice writeup. This however tries to encode all the hidden painter's knowledge. Would it be easier to generate realistic images from paintings and use these pairs to finetune an image generation model?
You can already use genAI to do similar things. The whole point, however, was to see what I could do using traditional techniques. The other benefit is that it's something you can run locally without needing a lot of resources, and have full control over the shape of the output. You can also combine this with generative models, and have a model generate a picture, then have this repaint it. Ultimately the point was to have some fun and play around with combining these techniques.
I used my own photos for the input, I find images with the subject isolated to be more visually pleasing, hence most of my photos are in this style. But there wouldn't be any difference to the algorithm if the image was full of detail as you can see with my photo of Hong Kong at the end.