python - 使用 openCV2 和 python 无法正确检测虹膜圈？

Question

我正在努力从眼睛图像中检测虹膜，但我得到的结果并不令人满意。如何检测精确的圆？我进行了很多搜索，但找不到任何结果。

import cv2
from matplotlib import pyplot as plt
img=cv2.imread(r" 

路径",cv2.IMREAD_COLOR)

gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# Blur using 3 * 3 kernel.
gray_blurred = cv2.blur(gray, (3, 3))

detected_circles = cv2.HoughCircles(gray_blurred,
                                cv2.HOUGH_GRADIENT, 1, 200, param1=400,
                                param2=6.787, minRadius=300, maxRadius=400)
if detected_circles is not None:

# Convert the circle parameters a, b and r to integers.
detected_circles = np.uint16(np.around(detected_circles))

for pt in detected_circles[0, :]:
    a, b, r = pt[0], pt[1], pt[2]

    # Draw the circumference of the circle.
    cv2.circle(img, (a, b), r, (0, 255, 0), 20)

    # Draw a small circle (of radius 1) to show the center.
    cv2.circle(img, (a, b), 10, (0, 0, 255), 3)
    imS = cv2.resize(img, (640, 480))
    cv2.imshow("Detected Circle", imS)
    cv2.waitKey(0)