Find pixels with a combo of saturation and brightness over X and return the percentage of those in the total pixel count

Question

I am trying to take an image and evaluate the total number of pixels that have a combination of saturation and brightness over a specific baseline in an image. This formula works properly.

sqrt(s/255. * v/255.)

A value of a medium red for example would be 0.5, where a totally saturated bright red would be 1. Returning the saturation isn't enough for the type of metric I wish to collect.

I want to return a single percentage of those pixels over the baseline, versus the total pixels in the image. I am a bit stuck trying to get this filter to work and to do the total calculation of the result versus the total pixels.

BASELINE = 0.8
pixels = hsv.reshape((hsv.shape[0] * hsv.shape[1], 3))
    for h,s,v in pixels:
      d[h] = sqrt(s/255. * v/255.)
      vibrant_px[h] = filter(lambda x: x > BASELINE, d)

How to total vibrant_px versus total pixels that are over BASELINE?

For the most part this works, but getting the total results from the tuple is frustrating me.