The problem was that to convert it properly without having too much noise I had to use (I think in english it's called) Luminosity Reduction.
In that way I could obtain very defined edges and everything. Then I went back to readd colors.
The problem is, that the image is now flattened, so to speak.
I'll include a comparison image.
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The outer frame is the Svg one where the extra details have ended flattened, while the interior one is the original one (ofc the original not being svg, it got pixelated in the zooming process).
Can you help me get back those details, or even just apply some kind of effect to mimic that original result?
Thank you so much,
Roberto