我正在为我的学校项目做学生检测。这是我第一次使用OpenCV和Python，使用Python version 3.4.2和opencv3.1.0。

我用的是覆盆子皮黑相机，我得到了很好的图像。

但我不能很好地察觉瞳孔(因为有闪光、睫毛和阴影)。

我在网上引用了一些代码，下面是代码的一部分。...

kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (5, 5))

# capture frames from the camera

for frame in camera.capture_continuous(rawCapture, format="bgr", use_video_port=True):

image = frame.array

cv2.imshow("image", image)

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

retval, thresholded = cv2.threshold(gray, 80, 255, 0)

cv2.imshow("threshold", thresholded)

closed = cv2.erode(cv2.dilate(thresholded, kernel, iterations=1), kernel, iterations=1)

#closed = cv2.morphologyEx(close, cv2.MORPH_CLOSE, kernel)

cv2.imshow("closed", closed)

thresholded, contours, hierarchy = cv2.findContours(closed, cv2.RETR_LIST, cv2.CHAIN_APPROX_NONE)

drawing = np.copy(image)

cv2.drawContours(drawing, contours, -1, (255, 0, 0), 2)

for contour in contours:

area = cv2.contourArea(contour)

bounding_box = cv2.boundingRect(contour)

extend = area / (bounding_box[2] * bounding_box[3])

# reject the contours with big extend

if extend > 0.8:

continue

# calculate countour center and draw a dot there

m = cv2.moments(contour)

if m['m00'] != 0:

center = (int(m['m10'] / m['m00']), int(m['m01'] / m['m00']))

cv2.circle(drawing, center, 3, (0, 255, 0), -1)

# fit an ellipse around the contour and draw it into the image

try:

ellipse = cv2.fitEllipse(contour)

cv2.ellipse(drawing, box=ellipse, color=(0, 255, 0))

except:

pass

# show the frame

cv2.imshow("Drawing", drawing)

...

输入图像：

输出图像：

如上图所示，如何去除图像中与瞳孔无关的部分？

除了答案，任何提示也欢迎。