python - 我正在尝试使用 OpenCV 和 Python 计算我眼睛的中心点

Question

我的程序可以检测我的左眼，但我希望它能够在检测到的区域的中心放置一个点。我尝试计算它，但它总是将点放置在左上角附近。任何想法/帮助将不胜感激。

import cv2


face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')

cap = cv2.VideoCapture(0)  # sets up webcam

while 1:  # capture frame, converts to greyscale, looks for faces
    ret, img = cap.read()
    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    faces = face_cascade.detectMultiScale(gray, 1.3, 5)

    for (x, y, w, h) in faces:  # draws box around face
        cv2.rectangle(img, (x, y), (x + int(w / 2), y + int(h / 2)), (255, 0, 0), 2)  # Draws Box Around Face
        roi_gray = gray[y:y + int(h / 2), x:x + int(w / 2)]  # slices grey area based off given parameters
        roi_color = img[y:y + h, x:x + w]  # selects region of interest (roi) based on color
        eyes = eye_cascade.detectMultiScale(roi_gray)  # looks for eyes
        for (ex, ey, ew, eh) in eyes:  # draws boxes around eyes
            eye_centerX = (ex+(ex+ew))/2
            eye_centerY = (ey+(ey+eh))/2
            eye_center_cord = eye_centerX, eye_centerY
            cv2.line(img, (int(eye_centerX), int(eye_centerY)), (int(eye_centerX), int(eye_centerY)), (0, 0, 0), 10)

    cv2.imshow('img', img)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

Answer 1

问题在于眼睛检测器模块一次只针对一只眼睛工作。即使您看到图像中两只眼睛被框起来，该 for 循环实际上与一只眼睛相关。

解决方案是将人脸框分成两部分并通过注视坐标分别检测左眼和右眼。

如果解释不够清楚，我可以通过编辑你的代码来解释。就说吧。

这是编辑后的代码:

import cv2
left_eye_point_x = 0
right_eye_point_x = 0
face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')

cap = cv2.VideoCapture(0)  # sets up webcam

while 1:  # capture frame, converts to greyscale, looks for faces
    ret, img = cap.read()
    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    faces = face_cascade.detectMultiScale(gray, 1.3, 5)

    for (x, y, w, h) in faces:  # draws box around face
        cv2.rectangle(img, (x, y), (x + int(w / 2), y + int(h / 2)), (255, 0, 0), 2)  #
        roi_gray = gray[y:y + int(h / 2), x:x + int(w / 2)]  
        roi_color = img[y:y + h, x:x + w]  
        eyes = eye_cascade.detectMultiScale(roi_gray)  # looks for eyes
        for (ex, ey, ew, eh) in eyes:  # draws boxes around eyes
           if (ex+ey)/2 < (x+y)/2:
                left_eye_point_x = (ex+ey)/2
            elif (ex+ey)/2 > (x+y)/2:
                right_eye_point_x = (ex+ey)/2
            cv2.line(img, (int(left_eye_point_x), int(right_eye_point_x)), (int(left_eye_point_x), int(right_eye_point_x)), (0, 0, 0), 10)

    cv2.imshow('img', img)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break