title: Are there known implementations of the CIEDE2000 or CIE94 Delta-E color difference calculation algorithm?
body: <p>I need to calculate the Delta-E distance between two colors. The algorithm to do so with two colors in CIELab color space looks like this:</p>
  
  <p><img src="https://i.stack.imgur.com/iOKtM.png" alt="enter image description here"></p>
  
  <p>Are there known open-sourced implementations of this algorithm? It's not hard to implement, but from my last attempt of implementing a color-space conversion algorithm I'd prefer to not re-develop the wheel when it's already on the road and tested.</p>
  
  <p>CIEDE2000 would be nice too and more accurate, but might also be overkill on the iPhone. CIE94 would be just fine I guess.</p>