Harris corner detection

OpenCV has the cv2.cornerHarris() function for detecting corners. Its arguments are as follows:

• img: The input image, which must be grayscale and have the float32 type.
• blockSize: This is the size of the neighborhood considered for corner detection.
• ksize: The aperture parameter of the Sobel derivative used.
• k: The free Harris detector parameter used in the equation.

The following is an example program that implements Harris corner detection:

import cv2
import numpy as np
import matplotlib.pyplot as plt
img = cv2.imread('/home/pi/book/dataset/4.1.05.tiff', 0)
img = np.float32(img)
dst = cv2.cornerHarris(img, 2, 3, 0.04)
ret, dst = cv2.threshold(dst, 0.01*dst.max(), 255, 0)
dst = np.uint8(dst)
plt.imshow(dst, cmap='gray')
plt.axis('off')
plt.show()

In the preceding program, we coverted the image into 32-bit float format and then we fed it to the corner detection function. Then, we threshholded the...