Python, OpenCV: Increasing image brightness without overflowing UINT8 array

Question

I am trying to increase brightness of a grayscale image. cv2.imread() returns a numpy array. I am adding integer value to every element of the array. Theoretica

Answer 1

Here is another alternative:

# convert data type
gray = gray.astype('float32')

# shift pixel intensity by a constant
intensity_shift = 50
gray += intensity_shift

# another option is to use a factor value > 1:
# gray *= factor_intensity

# clip pixel intensity to be in range [0, 255]
gray = np.clip(gray, 0, 255)

# change type back to 'uint8'
gray = gray.astype('uint8)