How to Display a Matplotlib RGB Image

matplotlib_with_opencv.py

import cv2
from matplotlib import pyplot as plt

img = cv2.imread('lena.jpg', -1)
cv2.imshow('image', img)
img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)

plt.imshow(img)
plt.xticks([]), plt.yticks([])
plt.show()

cv2.waitKey(0)
cv2.destroyAllWindows()

simple_thresholding_opencv_python.py

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

img = cv.imread('gradient.png',0)
_, th1 = cv.threshold(img, 50, 255, cv.THRESH_BINARY)
_, th2 = cv.threshold(img, 200, 255, cv.THRESH_BINARY_INV)
_, th3 = cv.threshold(img, 127, 255, cv.THRESH_TRUNC)
_, th4 = cv.threshold(img, 127, 255, cv.THRESH_TOZERO)
_, th5 = cv.threshold(img, 127, 255, cv.THRESH_TOZERO_INV)

titles = ['Original Image','BINARY','BINARY_INV','TRUNC','TOZERO','TOZERO_INV']
images = [img, th1 ,th2 ,th3 ,th4, th5]

for i in range(6):
    plt.subplot(2, 3, i+1), plt.imshow(images[i], 'gray')
    plt.title(titles[i])
    plt.xticks([]),plt.yticks([])
#cv.imshow("Image", img)
#cv.imshow("th1", th1)
#cv.imshow("th2", th2)
#cv.imshow("th3", th3)
#cv.imshow("th4", th4)
#cv.imshow("th5", th5)
plt.show()
#cv.waitKey(0)
#cv.destroyAllWindows()