util.py

import cv2
import numpy as np
from matplotlib import pyplot as plt
import math

def toRGB(img):
    return cv2.cvtColor(img, cv2.COLOR_BGR2RGB)

def toGrayscale(img):
    return cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

def toNegative(img):
    return cv2.bitwise_not(img)

def toSepia(img):
    sepiaImage = np.array(img, dtype=np.float64)
    sepiaImage = cv2.transform(sepiaImage,
                               np.matrix([[0.272, 0.543, 0.131], [0.349, 0.686, 0.168], [0.393, 0.769, 0.189]]))
    sepiaImage[np.where(sepiaImage > 255)] = 255
    sepiaImage = np.array(sepiaImage, dtype=np.uint8)

    return sepiaImage

def imageRead(path):
    return cv2.imread(path)

def plotShow(img):
    plt.imshow(toRGB(img))
    plt.show()