from glob import glob
import numpy as np
import cv2

color_min = np.array([140, 100,  100],np.uint8)
color_max = np.array([170, 255, 255],np.uint8)

for fname in glob('*.jpg'):
 orig_img = cv2.imread(fname)
 hsv_img = cv2.cvtColor(orig_img, cv2.COLOR_RGB2HSV)
 clr_f_img = cv2.bitwise_and(hsv_img, hsv_img, mask = cv2.inRange(hsv_img, color_min, color_max))
 bw_img = cv2.cvtColor(cv2.cvtColor(clr_f_img, cv2.COLOR_HSV2RGB), cv2.COLOR_RGB2GRAY)
 circles = cv2.HoughCircles(bw_img, cv2.HOUGH_GRADIENT, 400, 100, param2=500, minRadius=50, maxRadius=600)
 if circles is not None:
  for [x, y, r] in np.around(circles[0]):
   cv2.circle(orig_img, (x,y), r, (0,255,0), 3)
  cv2.imwrite(fname.replace('.jpg', '_out.jpg'), orig_img)