def test_normalize_brightness():
'''Test the function normalize_brightness in img_manip.'''
new_pic = create_pic(4, 4)
new_pic_normalized= img_manip.normalize_brightness(new_pic)
#The average brightness of new_pic_normalized will likely not be exactly 128
#because the RBG values are rounded to integer values after being multipled
#by the normalization factor, so the function tests for a difference of less
#than 2 rather than for equality.
new_avg_brightness = avg_bright.average_brightness(new_pic_normalized)
assert abs(new_avg_brightness - 128) < 2, \
"normalize_brightness failed to normalize the picture's average \
def normalize_brightness_GUI (label):
'''Implement the function normalize_brightness from img_manip.'''
#Clear all the temp pics in front of the current pic current_pic
global temp_label
global current_pic
temp_label = temp_label[0:current_pic+1]
#Implement the function normalize_brightness .
label.picture = img_manip.normalize_brightness(label.picture)
#Keep a copy of the current pic for the functions Undo and Redo
temp_label.append(label.picture)
current_pic += 1
#update the label
update_label(label)