opencv/samples/python/houghcircles.py
2021-02-21 23:02:16 +03:00

50 lines
1.3 KiB
Python
Executable File

#!/usr/bin/python
'''
This example illustrates how to use cv.HoughCircles() function.
Usage:
houghcircles.py [<image_name>]
image argument defaults to board.jpg
'''
# Python 2/3 compatibility
from __future__ import print_function
import numpy as np
import cv2 as cv
import sys
def main():
try:
fn = sys.argv[1]
except IndexError:
fn = 'board.jpg'
src = cv.imread(cv.samples.findFile(fn))
img = cv.cvtColor(src, cv.COLOR_BGR2GRAY)
img = cv.medianBlur(img, 5)
cimg = src.copy() # numpy function
circles = cv.HoughCircles(img, cv.HOUGH_GRADIENT, 1, 10, np.array([]), 100, 30, 1, 30)
if circles is not None: # Check if circles have been found and only then iterate over these and add them to the image
circles = np.uint16(np.around(circles))
_a, b, _c = circles.shape
for i in range(b):
cv.circle(cimg, (circles[0][i][0], circles[0][i][1]), circles[0][i][2], (0, 0, 255), 3, cv.LINE_AA)
cv.circle(cimg, (circles[0][i][0], circles[0][i][1]), 2, (0, 255, 0), 3, cv.LINE_AA) # draw center of circle
cv.imshow("detected circles", cimg)
cv.imshow("source", src)
cv.waitKey(0)
print('Done')
if __name__ == '__main__':
print(__doc__)
main()
cv.destroyAllWindows()