OpenCV人脸检测_眼睛检测之在人脸以外找眼睛

╰+哭是因爲堅強的太久メ 2023-07-14 10:57 22阅读 0赞

# OpenCV人脸检测\_眼睛检测之在人脸以外找眼睛 #

今天在学习opencv人脸检测时，发现眼睛检测是在人脸以外寻找眼睛的，源代码如下：

import cv2
    
    def detect():
        face_cascade = cv2.CascadeClassifier('../cascades/haarcascade_frontalface_default.xml')
        eye_cascade = cv2.CascadeClassifier('../cascades/haarcascade_eye.xml')
    
        camera = cv2.VideoCapture(0)
    
        while (True):
            ret , frame = camera.read()
            gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
            faces = face_cascade.detectMultiScale(gray, 1.3, 5)
            for (x,y,w,h) in faces:
                img = cv2.rectangle(frame, (x,y), (x+w, y+h), (255,0,0), 2)
    
                roi_gray = gray[y: y+h, x: x+w]
    
                eyes = eye_cascade.detectMultiScale(roi_gray, 1.8, 5, 0, (40,40))
    
                for (ex,ey,ew,eh) in eyes:
                    cv2.rectangle(img, (ex, ey), (ex+ew, ey+eh), (0, 255, 0), 2)
    
            cv2.imshow("camera", frame)
            if cv2.waitKey(int(1000 / 12)) & 0xff == ord("q"):
                break
    
        camera.release()
        cv2.destroyAllWindows()
    
    detect()

效果图如下：  
![未在人脸区域检测人脸][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM5NjI2NDY1_size_16_color_FFFFFF_t_70]  
后来一检查代码才发现问题，

cv2.rectangle(img, (ex, ey), (ex+ew, ey+eh), (0, 255, 0), 2)

这里面的img指的就是整张图片，而非人脸区域，因此要在该代码前面加上一句

roi_color = img[y:y + h, x:x + w]

完整代码如下：

import cv2
    
    def detect():
        face_cascade = cv2.CascadeClassifier('../cascades/haarcascade_frontalface_default.xml')
        eye_cascade = cv2.CascadeClassifier('../cascades/haarcascade_eye.xml')
    
        camera = cv2.VideoCapture(0)
    
        while (True):
            ret , frame = camera.read()
            gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
            faces = face_cascade.detectMultiScale(gray, 1.3, 5)
            for (x,y,w,h) in faces:
                img = cv2.rectangle(frame, (x,y), (x+w, y+h), (255,0,0), 2)
    
                roi_gray = gray[y: y+h, x: x+w]
    
                eyes = eye_cascade.detectMultiScale(roi_gray, 1.8, 5, 0, (40,40))
    
                roi_color = img[y:y + h, x:x + w]
    
                for (ex,ey,ew,eh) in eyes:
                    cv2.rectangle(roi_color, (ex, ey), (ex+ew, ey+eh), (0, 255, 0), 2)
    
            cv2.imshow("camera", frame)
            if cv2.waitKey(int(1000 / 12)) & 0xff == ord("q"):
                break
    
        camera.release()
        cv2.destroyAllWindows()
    
    detect()

现在的效果图如下：  
![在人脸区域寻找眼睛][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM5NjI2NDY1_size_16_color_FFFFFF_t_70 1]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM5NjI2NDY1_size_16_color_FFFFFF_t_70]: /images/20230529/4cf8d490a3924a97b6ffd3c1a5341f35.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM5NjI2NDY1_size_16_color_FFFFFF_t_70 1]: /images/20230529/254d5f26ea5e46cc95c74560df4db65c.png