画像から円弧で切り出してcountNonZero

main.py

#!/usr/bin/env python
# coding=utf-8

import cv2
import numpy as np

img = cv2.imread('./images/s01.png')
height, width, channels = img.shape

g_img = cv2.bilateralFilter(img, 9, 75, 75)
c_img = cv2.Canny(g_img, 50, 150)
cv2.imshow('filtered', c_img)

mask = np.zeros((height, width, 1), np.uint8)
cv2.ellipse(mask, center=(50, 100), axes=(100, 100), angle=0, startAngle=0, endAngle=-22.5, color=255, thickness=cv2.cv.CV_FILLED)
cv2.imshow('mask', mask)

masked = cv2.bitwise_and(c_img, c_img, mask=mask)
cv2.imshow('masked', masked)

print('countNonZero : {:d}'.format(cv2.countNonZero(masked)))

cv2.waitKey()
cv2.destroyAllWindows()