‹ BackHN Continuity

Thread

Show HN: Simple algorithm and color space to generate diverse skin tones

615 points · 99 comments · automatoney

  1. vermarish · · focus · HN ↗
    This is beautiful work! First, I thought this would involve using PCA to go from 3D to 2D, which would result in an easier selector to use, but at the expense of representing every person.

    Then, I thought this would stop at using the U-space vectors (the ones that form the basis of the PCA image) and their corresponding ellipse to form our color space, but no, the function fitting is a very slick idea, even if it was executed by hand.

    Lastly, I love the presentation of sampling from different r values. Whether you sample from a fixed r value or a range of r values, I bet this has great applications in game design or animation.

    I still don't quite get the manual data labeling process at the beginning? It seems like it would encode some bias, but the consistency of the first point cloud and the results certainly speak for themselves.

    1. dr_scully · · focus · HN ↗
      If you look at my doctoral thesis, in fact skin colour can be parametrised using melanin and haemoglobin concentration; which it means it is indeed (roughly) two dimensional. This allows you to invert the colour of a pixel and identify someone’s chromophore concentration. This is based on previous work of others cited in the thesis.

      <a href="https:&#x2F;&#x2F;discovery.ucl.ac.uk&#x2F;id&#x2F;eprint&#x2F;10093345&#x2F;" rel="nofollow">https:&#x2F;&#x2F;discovery.ucl.ac.uk&#x2F;id&#x2F;eprint&#x2F;10093345&#x2F;

      1. GolDDranks · · focus · HN ↗
        I&#x27;ve heard that the so-called &quot;yellowish&quot; skin color that non-tanned East Asians tend to have, is due to relative abundance of subcutaneous fat. If that&#x27;s true, is that captured by the haemoglobin dimension or is it a yet another degree of freedom?
        1. skydhash · · focus · HN ↗
          Not an expert, but when I was learning 3d modeling, there was a good chapter on subsurface scattering which affect the human skin rendering. It’s what give it liveness instead of looking like a doll.
Open on Hacker News to reply ↗

Unofficial Hacker News client; not affiliated with Y Combinator.