Inkscape - Linearize effect

import coloreffect
import math

class C(coloreffect.ColorEffect):
  def colmod(self,r,g,b):
    r = float(r) / 255
    g = float(g) / 255
    b = float(b) / 255
    r = pow(r, 0.45)
    g = pow(g, 0.45)
    b = pow(b, 0.45)
    r = int(r * 255)
    g = int(g * 255)
    b = int(b * 255)
    return '%02x%02x%02x' % (r,g,b)

c = C()
c.affect()