5_corner_detection.py

import cv2
import numpy as np

img = cv2.imread("assets/shapes.png")
gray_img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# SHI-TOMASI METHOD
corners = cv2.goodFeaturesToTrack(gray_img, maxCorners=50,
                qualityLevel=0.15, minDistance=50)
corners = np.int0(corners)

for c in corners:
    x, y = c.ravel()
    img = cv2.circle(img, center=(x, y), radius=20, 
                    color=(0, 0, 255), thickness=-1)

# HARRIS CORNER DETECTION
corners = cv2.goodFeaturesToTrack(gray_img, maxCorners=50,
                qualityLevel=0.01, minDistance=50,
                useHarrisDetector=True, k=0.1)
corners = np.int0(corners)

for c in corners:
    x, y = c.ravel()
    img = cv2.circle(img, center=(x, y), radius=10, 
                    color=(0, 254, 0), thickness=-1)

cv2.imshow("Shape", img)
cv2.waitKey(0)
cv2.destroyAllWindows()

cv2.imwrite("assets/5_shape_w_corners.png", img)