HSPB Algorithm

[oaustegard]

As determined by testing #13 and #16 the approach of basing hue on the primary vivid color and the brightness on the primary overall color may not be particularly useful. Instead let's attempt to get a Hue, Saturation and Perceived Brightness of each pixel.

Subsequently (in #20) extract all vivid colored pixels from the image (Saturation (0.15, 1], PB (0.18, 0.95)), partition the overall image hue into a band, then sort by overall image perceived brightness (simple sum of all pixels/number of pixels).