Neltner Labs

Fun Projects and Art

New 7-Channel LZ7 LED with full CIE LUV Color and Gamma Correction

This was a fun project. I got a sample of the new LEDEngin LZ7 LED, which has on a single chip red, amber, green, cyan, blue, violet, and white. While I already have a great algorithm for converting HSI to RGBW, this is a much more complex challenge – converting from HSI to RAGCBVW.

The constraint I used is that the color must use only 2 individual LED wavelengths, plus white for saturation control.

To do this, I used the CIE LUV colorspace, shown below. This provides uniform perceptual color changes in hue and linear perceptual brightness as hue changes.

(“CIE 1976 UCS” by Adoniscik - Own work. Licensed under Public Domain via Wikimedia Commons -

The results are very nice, you can check them out in this video. Unfortunately the CCD (and your monitor) can’t actually represent the violet, amber, and cyan colors accurately, but so it goes.

Brian NeltnerComment