def lighting(im, b, c):
if b==<NUM_LIT:0> and c==<NUM_LIT:1>: return im<EOL>mu = np.average(im)<EOL>return np.clip((im-mu)*c+mu+b,<NUM_LIT:0.>,<NUM_LIT:1.>).astype(np.float32)<EOL>
adjusts image's balance and contrast