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

img = cv.imread('Resources/Photos/cats.jpg')
cv.imshow('Cats',img)

blank = np.zeros(img.shape[:2],dtype='uint8')

gray = cv.cvtColor(img, cv.COLOR_BGR2GRAY)
# cv.imshow('GRAY',gray)

mask = cv.circle(blank, (img.shape[1]//2,img.shape[0]//2),100,255,-1)

masked = cv.bitwise_and(img,img,mask=mask)
cv.imshow('MASK',masked)

# Grayscale histogram
# gray_hist = cv.calcHist([gray], [0], mask, [256],[0,256])

# plt.figure()
# plt.title('Grayscale Histogram')
# plt.xlabel('Bins')
# plt.ylabel('# og pixels')
# plt.plot(gray_hist)
# plt.xlim([0,256])
# plt.show()

# Colour Histogram
plt.figure()
plt.title('Colour Histogram')
plt.xlabel('Bins')
plt.ylabel('# og pixels')
colours = ('b','g','r')
for i,col in enumerate(colours):
    hist = cv.calcHist([img],[i],mask, [256],[0,256])
    plt.plot(hist,color=col)
    plt.xlim([0,256])
plt.show()

cv.waitKey(0)