29_Histogram_and_Back_Projection.py

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

original_image = cv2.imread("./images/goalkeeper.jpg")
hsv_original = cv2.cvtColor(original_image, cv2.COLOR_BGR2HSV)

roi = cv2.imread('./images/pitch_ground.jpg')
hsv_roi = cv2.cvtColor(roi, cv2.COLOR_BGR2HSV)

hue, saturation, value = cv2.split(hsv_roi)

# Histogram ROI
roi_hist = cv2.calcHist([hsv_roi], [0, 1], None, [180, 256], [0, 180, 0, 256])
mask = cv2.calcBackProject([hsv_original], [0, 1],
                           roi_hist, [0, 180, 0, 256], 1)

# Filtering remove noise
kernel = cv2.getStructuringElement(cv2.MORPH_ELLIPSE, (5, 5))

# Show the kernel
for i in kernel:
    print(i)

mask = cv2.filter2D(mask, -1, kernel)
_, mask = cv2.threshold(mask, 100, 255, cv2.THRESH_BINARY)
mask = cv2.merge((mask, mask, mask))
result = cv2.bitwise_and(original_image, mask)

# Show iamges
cv2.imshow("Mask", mask)
cv2.imshow("Original image", original_image)
cv2.imshow("Result", result)
cv2.imshow("Roi", roi)

cv2.waitKey(0)
cv2.destroyAllWindows()