luminanceCheck_b

def luminanceCheck_b(pict1,pict2):
#@param:
#   pict1, pict2: picture;
#   return: bool;
    allPix1 = getPixels(pict1)
    allPix2 = getPixels(pict2)
    return exist_univ(allPix1,allPix2)

#-------------------------------------------------------------------------------
def lumCheck(pix1,pix2):
#@param:
#   pix1, pix2: pixel;
#   return: bool;
  if luminance(pix1) == luminance(pix2):
    return True
  else:
    return False
#-------------------------------------------------------------------------------
def luminance(pix):
#@param:
#   pix: pixel
#   return: int, luminance;
    r = getRed(pix)
    g = getGreen(pix)
    b = getBlue(pix)
    luminance = (r+g+b)/3
    return (luminance)
#-------------------------------------------------------------------------------
def exist_univ(D1,D2):
#@param:
#   D1, D2: list of items;
#   return: bool;
    for item in D1:
        if univ(item,D2):
            return True
    return False
#-------------------------------------------------------------------------------
def univ(x,D1):
# Universal quantifier "for every";
#@param:
#   x: item;
#   D: list of items;
#   return: bool;
    for item in D1:
        if not lumCheck(x,item):
            return False
    return True