add ocv_find_corners.py

ocv_find_corners.py

@@ -0,0 +1,74 @@
+from __future__ import print_function
+import cv2 as cv
+import numpy as np
+import argparse
+import random as rng
+
+source_window = 'Image'
+maxTrackbar = 25
+rng.seed(12345)
+
+
+def goodFeaturesToTrack_Demo(val):
+	maxCorners = max(val, 1)
+
+	# Parameters for Shi-Tomasi algorithm
+	qualityLevel = 0.01
+	minDistance = 10
+	blockSize = 3
+	gradientSize = 3
+	useHarrisDetector = False
+	k = 0.04
+
+	# Copy the source image
+	copy = np.copy(src)
+
+	# Apply corner detection
+	corners = cv.goodFeaturesToTrack(src_gray, maxCorners, qualityLevel, minDistance, None, \
+									 blockSize=blockSize, gradientSize=gradientSize,
+									 useHarrisDetector=useHarrisDetector, k=k)
+
+	# Draw corners detected
+	print('** Number of corners detected:', corners.shape[0])
+	radius = 4
+	for i in range(corners.shape[0]):
+		cv.circle(copy, (int(corners[i, 0, 0]), int(corners[i, 0, 1])), radius,
+				  (rng.randint(0, 256), rng.randint(0, 256), rng.randint(0, 256)), cv.FILLED)
+
+	# Show what you got
+	cv.namedWindow(source_window)
+	cv.imshow(source_window, copy)
+
+	# Set the needed parameters to find the refined corners
+	winSize = (5, 5)
+	zeroZone = (-1, -1)
+	criteria = (cv.TERM_CRITERIA_EPS + cv.TermCriteria_COUNT, 40, 0.001)
+
+	# Calculate the refined corner locations
+	corners = cv.cornerSubPix(src_gray, corners, winSize, zeroZone, criteria)
+
+	# Write them down
+	for i in range(corners.shape[0]):
+		print(" -- Refined Corner [", i, "] (", corners[i, 0, 0], ",", corners[i, 0, 1], ")")
+
+
+# Load source image and convert it to gray
+parser = argparse.ArgumentParser(description='Code for Shi-Tomasi corner detector tutorial.')
+parser.add_argument('--input', help='Path to input image.', default='pic3.png')
+args = parser.parse_args()
+
+src = cv.imread('./data/spindle_bg_black/0001.png')
+if src is None:
+	print('Could not open or find the image:', args.input)
+	exit(0)
+
+src_gray = cv.cvtColor(src, cv.COLOR_BGR2GRAY)
+
+# Create a window and a trackbar
+cv.namedWindow(source_window)
+maxCorners = 10  # initial threshold
+cv.createTrackbar('Threshold: ', source_window, maxCorners, maxTrackbar, goodFeaturesToTrack_Demo)
+cv.imshow(source_window, src)
+goodFeaturesToTrack_Demo(maxCorners)
+
+cv.waitKey()